I've noticed when watching some films that some players are able to do instant and perfect 180 degree spins. For example, I come up from behind and start shooting and they instantly spin and are aiming right at me. Is there some kind of a mouse macro that they could be using for this? Is it just a result of the theater rendering the video incorrectly (I doubt this)?
I can't even move that fast without worrying about accuracy. Maybe if I turned the mouse sensitivity to max, but then I can't imagine aiming under normal conditions.
On a similar note, I also often see players whose aim seems almost mechanical. Not that I think that they're using an aimbot (they sometimes miss), but when faced with several enemies they aim at one perfectly, shoot a few times then the aim immediately "jolts" to the next enemy. Is this just a lot of practice or are there tricks to being able to do this?