Oh, it runs just fine; my issues with SLI are limited to a total of 3 games, other than that it's just fine. There's a well known bug with Fallout 3 concerning flickering HDR if you have SLI, but the issue goes away when SLI is disabled. TF2 gives me flickering freezecam shots whenever I die; this didn't use to happen before my most recent driver update, so I think that's to blame (issue also goes away with SLI disabled). Finally, Killing Floor crashes my display driver every 10 to 15 seconds if I use the direct3D 9.0 renderer with SLI enabled..this happened since I bought the game, which was after my most recent driver update.
Other than those 3 minor problems, which can either be ignored (in the case of Fallout 3 and TF2), or fixed (using the plain 'direct3D' renderer in Killing Floor).
The only reason I picked up the GX2 was 1.) It was cheap, considering the potential performance gains over my 8800gtx, and 2.) It was cheap, so I could try out SLI and see if it's technology I would spend more money on in the future. Since I game at a fairly modest resolution, 1680 by 1050, I can get by with a single monster card like the 8800gtx.
I'll probably wait for the next generation of nvidia/ati gpus coming out later this year, and get one of those, since in my specific situation, the benefits of SLI don't outweigh the introduction of dumb little bugs like the aforementioned three.
