And what difference does it make to have mouse acceleration or not?
If you are moving your mouse at one speed across a surface, without mouse acceleration your cursor will move at the speed of the mouse, with acceleration it'll start speeding up with the idea being that you're probably making a big movement so you'd appreciate going further in less time.
Now with the joysticks I like it when my cursor moves fast if I have the stick pushed all the way and moves more slowly if it's pushed part-way, the speed of the cursor should scale to the pushed-ness of the joystick. It's personal preference though.