The performance issue seems to effect navigation as well as playback, resulting in jerky video/audio in the menu and when watching a movie. This is also not limited to pesky DiVx files or QuickTime plug-ins either, as some users are reporting seeing the problem with iTunes purchases and others are even running a completely stock installation. Interestingly enough, some of the same users with Front Row issues are not seeing the same problems when playing back with QuickTime X.
In my opinion, this is not much of a surprise following such a major upgrade to many of the OS's underpinnings -- including an overhaul to QuickTime on which Front Row is largely based. This is the reason I did not upgrade the Mac mini in my living room. Aside from being a full-time webserver, I also rely on it for multimedia functionality as well.
Some folks with complaints have found solace in either Plex or Boxee as these fine media players do not rely on QuickTime or iTunes. For most though, a working Front Row would be ideal. Personally, I have not checked for problems with Front Row since my multimedia Mac hasn't been upgraded. However, I did note some wonkiness on another machine when using QuickLook to playback some video files through Finder. I have a sneaking suspicion there is something going on related to QuickTime X being used by other programs (i.e. FrontRow or QuickLook). What say you dear readers? Is your Front Row experience causing you grief or are you simply smirking because you haven't
Thanks to Ivey for sending this in via Twitter.