From the people that have been able to intelligently word their thoughts on the official forums, the two biggest changes appear to be that the deadzone is a wee bit smaller so the accel feels more linear now, and there is less inertia when turning so you're less likely to overcorrect when aiming -- the crosshairs stop when you stop. Otherwise, the "feel" is the same.
Essentially, the tweaks are so minor that if you didn't have a problem before, you probably won't notice the change now, and if you did think it was a problem before, this should make the crosshair a bit more representative of what you intended to do and less erratic.