I can not uninstall APC beta4 from a developed site, it's a serious problem.
I have tried even on fresh Drupal 7.15 installation. Once the APC module installed much work to remove it manually, uninstall leaves some problems.
I can't even move my drupal site from APC to non-APC hosting, both non-APC won't accept APC module debris in /includes cache.inc, cache_bootstrap.inc, etc. and on APC hosting the module can not be completely removed either.