Users of a mouse on Windows, what was not the shock of seeing how to react this same mouse in Mac OS X! No, the mouse is not defective, missing no batteries, it's just that OS X has its own management of acceleration.
When you slow down the movement of your mouse, the cursor slows proportionally its movement. This is the desired with the trackpad and it is very effective in this case. But only in this case! When you resume your good old mouse, it becomes very difficult to use as the cursor movement is inconsistent. Micro-deplacements (including to click the x to close a window) quickly become an ordeal as the cursor moves infinitely slowly.
Fortunately there is a solution: Smooth Mouse! This software will help you regain an acceleration and mouse movements such as you know them under Windows.
You can define an acceleration in Windows, like in OS X or remove it. You can also set the speed and all independently for the trackpad and mouse.
Indeed "OS X will never be the same"!