Originally posted by EDS66
Subjectively, Windows mouse acceleration feels more responsive, faster, easier. That's all.
Well, yes, at lower mouse speeds, the cursor is the same speed. It's a 1-to-1 ratio regardless of how fast or slow you move the mouse. That doesn't mean it's better.
Why is the Mac way better? Even Microsoft has conceded that the Mac way is better and implemented a similar curve to the acceleration in Windows XP.Precision.
Simply put, by slowing the cursor, it's easier to settle on small targets on the screen.
This is loosely related to Fitt's Law (the time to aquire a target is proportional to the distance to the target and inversely proportional to its size). By using an acceleration curve like Mac OS X, you effectively increase the size of the target as you move your mouse slower in approaching it. The result is a target that is easier to hit and less likely to overshoot.