There's an fps cap of 60, or your monitor's refresh rate. Disabling vsync set's fps at your refresh rate (i know, even though vsync does the same thing). There are ways around the cap, but since there's no raw input, and your mouse sensitivity is tied to fps, having fps that wavers at all really messes with your aim because your sensitivity bounces with your fps. It's really annoying and must be fixed prior to release. Having blown all that hot air... with 332.50 quadro I see no stutter and (vsync disabled) no fps drops. Occasionally it will hit 57 (lol), but it stays at a constant 60. I use insane textures, 4xmsaa, everything else high as it goes.