On a form with a few different textareas that contained input formats, I found that Better Formats is causing duplicate queries per page load. The problem is caused by Better Formats' call to _filter_tips(), which arguably it shouldn't be calling anyway.

_filter_tips() contains the following code:

function _filter_tips($format, $long = FALSE) {
  if ($format == -1) {
    $formats = filter_formats();
  else {
    $formats = array(db_fetch_object(db_query("SELECT * FROM {filter_formats} WHERE format = %d", $format)));

Since Better Formats passes in a $format ID, it does a SQL query per format, even though all the filter formats have already been loaded and staticly cached in filter_formats(). Clearly this is rather poor programing on the core side, but it would be appropriate for Better Formats to make it's own version of _filter_tips() in which it can produce the same output without any additional queries by passing in the format rather than needing to pull it from the database.