Well, you're right - the memcache api is overriding the cache_get and cache_set functions in standard Drupal to read/write to memcache instead of to the tables.
You do still need to turn on the performance options to get the full benefit of that - such as the page cache, block caching, and so on. That said, block caching can be a bit odd if someone's not been paying attention as they've created custom blocks - by default blocks get cached by role, but sometimes you want something more specific than that... I suggest turning the performance optimizations on and doing some testing... hopefully you can clone off a dev copy of the site. -- John Fiala www.jcfiala.net
