I recently purchased a 8600gt for the other half's computer which is strictly to run FS9 - not realising that AA does not work with any Nvidia 8 series cards and FS9!!!!
So anyway, have currently put it in my pc in place of my 8800gtx and am going to play around with it a bit.
Currently i have only tried a couple of games, and I plan to do a nice little write up for it, but so far I can say it is a better card than I thought it would be.
Sure it may not perform as well as a 1950 Pro, but it also cost £20 less than said 1950 pro.
F.E.A.R runs wery well at medium, and what surprised me was that at Max settings, it still maintained pretty much playable frame rates for most people - above 30.
Tomb Raider Anniversary runs brilliantly with 4xAA at 1440 x 900. This one surprised me the most.
Oblivio and GRAW both suffer from the same problem (which I have experienced before with my 8800gtx in oblivion) in that while it maintains playable frame rates, there is a strange jerking as if frames are being dropped or soemthing like that. And this is not the loading stutter when entering new areas. Although from brief testing so far seems only to be with outside areas in oblivion.
FSX with the same settings I used with my 8800gtx, was running between 15 and 20 fps.
Anyway, enough rambling from me. Will do a nice review of it with a few more games soon.