I have my mouse aiming and FOV set perfect for me. I went into User.ini and replaced all instances of "Speed=2000" with "Speed=500". This slowed the mouse aiming down and greatly nullified the acceleration. I had to crank the in-game sensitivity up to 5 to compensate. Now the aim is slow enough to be controllable, but not too slow. It's as fluid as any other FPS I've played now. I have a Logitech G500 running at 5700dpi. I set my FOV to 110, which gave a slight tunnel vision effect. I find that his helps me aim a lot better since the center of rotation of the camera is behind me instead of on top of me. I play RTCW:ET with 110 FOV so I'm really used to it. On top of that vsync is disabled so I get absolutely no mouse lag at all.