I haven't had a chance to exercise things under Update 9 so I can't comment on the Mac Client and crashes yet, but the FPS issue seems related to the SMC issues that Toddlepip pointed out. I have a mid-2010 27 inch iMac which suffers from the infamous Wi-Fi issue. I just had the disk-drive recall serviced and have noted that since having gotten it fixed around Thanksgiving, it has returned! (Wi-Fi randomly drops connection.) Fortunately it is still under Apple Care, so I'll have to give them a call again and find out what we did to fix it back then. I know we deleted some .plist file in /system, but I never wrote the information down. (silly me, I thought it was fixed!) But the interesting possibility is that the actual problem is a "corrupt" (whatever that means) plist file IN the Mountain Lion Distribution!
However, the interesting thing was that the "trick" to deleting the particular file was to power the system down -- not shut it down!
Because the particular file is maintained in memory and written back out (in its corrupt form) during shutdown. Deleting it causes start-up to re-write the file as it should be.
Other than that... remember you really can't compare a Bootcamp experience with OSX... because other than proving that the hardware itself is not the issue, Bootcamp is running a real copy of Windows with no portion of OSX involved.
Bill Magill - Mac Player - Old Timers Guild- Gladden:
Valamar: Dwarf Hunter - Level 100
Valdicta: Dwarf Rune-keeper - Level 100
Valanne: Beorning - Level 80