Okay, so I tried this, and when ever I enable it, it won't let me get into my admin control panel.Sessions from the Cache
If you have defined a cache in your config file, using memcached, APC, the file cache or any of the other options, XenForo will now store its visitor session data in that cache rather than the database, saving two queries per page. On a busy site, this can be a huge performance boost.
Note that while this feature was in beta 4, to continue using it, you must add this line to library/config.php:
$config['cache']['cacheSessions'] = true;
Like I click in login, and it does the animation and then resets and then i click on login again and it does the animation and resets... not sure why...
Thats the only problem I could find. I do have APC enabled.