diff --git a/core/includes/config.inc b/core/includes/config.inc
index 303c316..e17c788 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -4,6 +4,7 @@ use Drupal\Core\Config\Config;
 use Drupal\Core\Config\ConfigException;
 use Drupal\Core\Config\DatabaseStorage;
 use Drupal\Core\Config\FileStorage;
+use Drupal\Core\Config\NullStorage;
 use Drupal\Core\Config\StorageInterface;
 
 /**
@@ -25,12 +26,22 @@ function config_install_default_config($module) {
   if (is_dir($module_config_dir)) {
     $source_storage = new FileStorage(array('directory' => $module_config_dir));
     $target_storage = new DatabaseStorage();
-
-    $config_changes = config_sync_get_changes($source_storage, $target_storage);
+    $null_storage = new NullStorage();
+
+    // Upon module installation, only new config objects need to be created.
+    // config_sync_get_changes() would potentially perform a diff of hundreds or
+    // even thousands of config objects that happen to be contained in the
+    // active store. We leverage the NullStorage to avoid that needless
+    // computation of differences.
+    $config_changes = config_sync_get_changes($source_storage, $null_storage);
     if (empty($config_changes)) {
       return;
     }
-    $remaining_changes = config_import_invoke_sync_hooks($config_changes, $source_storage, $target_storage);
+    // Upon re-installation, potentially stale and pre-existing config objects,
+    // having the same names as default configuration objects, need to be
+    // deleted before creating the new default config.
+    $config_changes['delete'] = $config_changes['create'];
+    $remaining_changes = config_import_invoke_owner($config_changes, $source_storage, $target_storage);
     config_sync_changes($remaining_changes, $source_storage, $target_storage);
   }
 }
@@ -147,7 +158,7 @@ function config_import() {
   }
 
   try {
-    $remaining_changes = config_import_invoke_sync_hooks($config_changes, $source_storage, $target_storage);
+    $remaining_changes = config_import_invoke_owner($config_changes, $source_storage, $target_storage);
     config_sync_changes($remaining_changes, $source_storage, $target_storage);
     // Flush all caches and reset static variables after a successful import.
     drupal_flush_all_caches();
@@ -162,12 +173,18 @@ function config_import() {
 }
 
 /**
- * Invokes hook_config_import() implementations for configuration changes.
+ * Invokes MODULE_config_import() callbacks for configuration changes.
  *
  * @param array $config_changes
  *   An array of changes to be loaded.
+ * @param Drupal\Core\Config\StorageInterface $source_storage
+ *   The storage to synchronize configuration from.
+ * @param Drupal\Core\Config\StorageInterface $target_storage
+ *   The storage to synchronize configuration to.
+ *
+ * @todo Add support for other extension types; e.g., themes etc.
  */
-function config_import_invoke_sync_hooks(array $config_changes, StorageInterface $source_storage, StorageInterface $target_storage) {
+function config_import_invoke_owner(array $config_changes, StorageInterface $source_storage, StorageInterface $target_storage) {
   $storage_dispatcher = drupal_container()->get('config.storage.dispatcher');
 
   // Allow modules to take over configuration change operations for
@@ -186,8 +203,14 @@ function config_import_invoke_sync_hooks(array $config_changes, StorageInterface
         $old_config
           ->setName($name)
           ->load();
+        if ($op == 'delete' && $old_config->isNew()) {
+          continue;
+        }
 
         $data = $source_storage->read($name);
+        if ($op == 'create' && $data === FALSE) {
+          continue;
+        }
         $new_config = new Config($storage_dispatcher);
         $new_config
           ->setName($name)
diff --git a/core/lib/Drupal/Core/Config/Config.php b/core/lib/Drupal/Core/Config/Config.php
index 0748b76..457df57 100644
--- a/core/lib/Drupal/Core/Config/Config.php
+++ b/core/lib/Drupal/Core/Config/Config.php
@@ -20,6 +20,13 @@ class Config {
   protected $name;
 
   /**
+   * Whether the configuration object is new or has been saved to the storage.
+   *
+   * @var bool
+   */
+  protected $isNew = TRUE;
+
+  /**
    * The data of the configuration object.
    *
    * @var array
@@ -60,6 +67,13 @@ class Config {
   }
 
   /**
+   * Returns whether this configuration object is new.
+   */
+  public function isNew() {
+    return $this->isNew;
+  }
+
+  /**
    * Gets data from this config object.
    *
    * @param $key
@@ -210,6 +224,7 @@ class Config {
   public function load() {
     $this->setData(array());
     $data = $this->storageDispatcher->selectStorage('read', $this->name)->read($this->name);
+    $this->isNew = ($data === FALSE);
     if ($data !== FALSE) {
       $this->setData($data);
     }
@@ -222,6 +237,7 @@ class Config {
   public function save() {
     $this->sortByKey($this->data);
     $this->storageDispatcher->selectStorage('write', $this->name)->write($this->name, $this->data);
+    $this->isNew = FALSE;
     return $this;
   }
 
@@ -251,6 +267,7 @@ class Config {
   public function delete() {
     $this->data = array();
     $this->storageDispatcher->selectStorage('write', $this->name)->delete($this->name);
+    $this->isNew = TRUE;
     return $this;
   }
 }
diff --git a/core/lib/Drupal/Core/Config/DatabaseStorage.php b/core/lib/Drupal/Core/Config/DatabaseStorage.php
index 1dd8507..f30011c 100644
--- a/core/lib/Drupal/Core/Config/DatabaseStorage.php
+++ b/core/lib/Drupal/Core/Config/DatabaseStorage.php
@@ -51,7 +51,7 @@ class DatabaseStorage implements StorageInterface {
    *   Only thrown in case $this->options['throw_exception'] is TRUE.
    */
   public function read($name) {
-    $data = array();
+    $data = FALSE;
     // There are situations, like in the installer, where we may attempt a
     // read without actually having the database available. In this case,
     // catch the exception and just return an empty array so the caller can
@@ -114,7 +114,7 @@ class DatabaseStorage implements StorageInterface {
    */
   public static function decode($raw) {
     $data = @unserialize($raw);
-    return $data !== FALSE ? $data : array();
+    return is_array($data) ? $data : FALSE;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Config/FileStorage.php b/core/lib/Drupal/Core/Config/FileStorage.php
index 7827dc0..d9e7a5a 100644
--- a/core/lib/Drupal/Core/Config/FileStorage.php
+++ b/core/lib/Drupal/Core/Config/FileStorage.php
@@ -70,18 +70,15 @@ class FileStorage implements StorageInterface {
    */
   public function read($name) {
     if (!$this->exists($name)) {
-      return array();
+      return FALSE;
     }
     $data = file_get_contents($this->getFilePath($name));
     // @todo Yaml throws a ParseException on invalid data. Is it expected to be
     //   caught or not?
     $data = $this->decode($data);
-    if ($data === FALSE) {
-      return array();
-    }
     // A simple string is valid YAML for any reason.
     if (!is_array($data)) {
-      return array();
+      return FALSE;
     }
     return $data;
   }
@@ -131,6 +128,7 @@ class FileStorage implements StorageInterface {
    * @throws Symfony\Component\Yaml\Exception\ParseException
    */
   public static function decode($raw) {
+    // @todo An empty file means bogus config data; return FALSE?
     if (empty($raw)) {
       return array();
     }
diff --git a/core/lib/Drupal/Core/Config/NullStorage.php b/core/lib/Drupal/Core/Config/NullStorage.php
new file mode 100644
index 0000000..54554c9
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/NullStorage.php
@@ -0,0 +1,61 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Config\NullStorage.
+ */
+
+namespace Drupal\Core\Config;
+
+/**
+ * Defines the Null storage controller.
+ */
+class NullStorage implements StorageInterface {
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::__construct().
+   */
+  public function __construct(array $options = array()) {
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::read().
+   */
+  public function read($name) {
+    return array();
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::write().
+   */
+  public function write($name, array $data) {
+    return FALSE;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::delete().
+   */
+  public function delete($name) {
+    return FALSE;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::encode().
+   */
+  public static function encode($data) {
+    return $data;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::decode().
+   */
+  public static function decode($raw) {
+    return $raw;
+  }
+
+  /**
+   * Implements Drupal\Core\Config\StorageInterface::listAll().
+   */
+  public function listAll($prefix = '') {
+    return array();
+  }
+}
diff --git a/core/lib/Drupal/Core/Config/StorageInterface.php b/core/lib/Drupal/Core/Config/StorageInterface.php
index 907e884..806ee87 100644
--- a/core/lib/Drupal/Core/Config/StorageInterface.php
+++ b/core/lib/Drupal/Core/Config/StorageInterface.php
@@ -30,9 +30,9 @@ interface StorageInterface {
    * @param string $name
    *   The name of a configuration object to load.
    *
-   * @return array
+   * @return array|bool
    *   The configuration data stored for the configuration object name. If no
-   *   configuration data exists for the given name, an empty array is returned.
+   *   configuration data exists for the given name, FALSE is returned.
    */
   public function read($name);
 
diff --git a/core/modules/config/config.api.php b/core/modules/config/config.api.php
index 8f95d32..c50c2f9 100644
--- a/core/modules/config/config.api.php
+++ b/core/modules/config/config.api.php
@@ -15,11 +15,11 @@
 /**
  * Synchronize configuration changes.
  *
- * This hook is invoked when configuration is synchronized between storages and
- * allows a module to take over the synchronization of configuration data.
+ * This callback is invoked when configuration is synchronized between storages
+ * and allows a module to take over the synchronization of configuration data.
  *
- * Modules should implement this hook if they manage higher-level configuration
- * data (such as image styles, node types, or fields), which needs to be
+ * Modules should implement this callback if they manage configuration data
+ * (such as image styles, node types, or fields), which needs to be
  * prepared and passed through module API functions to properly handle a
  * configuration change.
  *
@@ -33,24 +33,31 @@
  * @param Drupal\Core\Config\DrupalConfig $old_config
  *   A configuration object containing the old configuration data.
  */
-function hook_config_import($op, $name, $new_config, $old_config) {
-  // Only image styles require custom handling. Any other module settings can be
-  // synchronized directly.
-  if (strpos($name, 'image.style.') !== 0) {
+function MODULE_config_import($op, $name, $new_config, $old_config) {
+  // Only configurable thingies require custom handling. Any other module
+  // settings can be synchronized directly.
+  if (strpos($name, 'config_test.dynamic.') !== 0) {
     return FALSE;
   }
 
   if ($op == 'delete') {
-    $style = $old_config->get();
-    return image_style_delete($style);
+    // @todo image_style_delete() supports the notion of a "replacement style"
+    //   to be used by other modules instead of the deleted style. Essential!
+    //   But that is impossible currently, since the config system only knows
+    //   about deleted and added changes. Introduce an 'old_ID' key within
+    //   config objects as a standard?
+    $config_test = new ConfigTest($old_config);
+    $config_test->delete();
   }
   if ($op == 'create') {
-    $style = $new_config->get();
-    return image_style_save($style);
+    $config_test = new ConfigTest($new_config);
+    $config_test->save();
   }
   if ($op == 'change') {
-    $style = $new_config->get();
-    return image_style_save($style);
+    $config_test = new ConfigTest($new_config);
+    $config_test->setOriginal($old_config);
+    $config_test->save();
   }
+  return TRUE;
 }
 
diff --git a/core/modules/config/config_test/config_test.module b/core/modules/config/config_test/config_test.module
index 5f229ca..8d4e8ec 100644
--- a/core/modules/config/config_test/config_test.module
+++ b/core/modules/config/config_test/config_test.module
@@ -19,12 +19,6 @@ function config_test_config_import($op, $name, $new_config, $old_config) {
   }
 
   if ($op == 'delete') {
-    // @todo image_style_delete() supports the notion of a "replacement style"
-    //   to be used by other modules instead of the deleted style. Good idea.
-    //   But squeezing that into a "delete" operation is the worst idea ever.
-    //   Regardless of Image module insanity, add a 'replaced' stack to
-    //   config_import()? And how can that work? If an 'old_ID' key would be a
-    //   standard, wouldn't this belong into 'changed' instead?
     $config_test = new ConfigTest($old_config);
     $config_test->delete();
   }
diff --git a/core/modules/image/image.module b/core/modules/image/image.module
index c95af19..28afd0b 100644
--- a/core/modules/image/image.module
+++ b/core/modules/image/image.module
@@ -511,11 +511,10 @@ function image_config_import($op, $name, $new_config, $old_config) {
 
   if ($op == 'delete') {
     // @todo image_style_delete() supports the notion of a "replacement style"
-    //   to be used by other modules instead of the deleted style. Good idea.
-    //   But squeezing that into a "delete" operation is the worst idea ever.
-    //   Regardless of Image module insanity, add a 'replaced' stack to
-    //   config_import()? And how can that work? If an 'old_ID' key would be a
-    //   standard, wouldn't this belong into 'changed' instead?
+    //   to be used by other modules instead of the deleted style. Essential!
+    //   But that is impossible currently, since the config system only knows
+    //   about deleted and added changes. Introduce an 'old_ID' key within
+    //   config objects as a standard?
     $style = $old_config->get();
     return image_style_delete($style);
   }