[development] testing performance?

instead of hijacking my own thread in the initial post, i figured i should start a new thread about this... ;) one of the things killes asked about in http://drupal.org/node/18018 (the blocks-by-roles issue) was testing/reviewing the performance implications of this patch. is there a good node @ drupal.org that provides suggestions/best practices for performance testing in various environments? is this the best thing going: http://drupal.org/node/43478#comment-80933 ??? thanks for any wisdom anyone can share. -derek (dww)