How the forget do you aim with one of those things. I never understand you people.
I know right. You tilt the brown townog stick a little and you have a loving spasm and end up turned 90 degrees, you turn back and have another spasm and can never get it where you need it. So you turn down the sensitivity, and now you can aim but it takes like 10 loving seconds because your crosshair moves so damn slow, and then someone's behind you and you have turn around like some paralyzed grandma with arthritis. Mice will always be better for aiming.
For movement, though, I prefer a stick over WASD. I think it has to do with the fact that my first game was a 3D platformer (Super Mario Galaxy - I started playing video games pretty late in life), which used a stick for running, and most of my games either played like that or were 2D platformers. The first time I played a game where you actually had to move the camera, it was on PC, so I got used to a mouse.
I actually quit Portal 2 on PS3 because I REALLY couldn't stand how I couldn't place portals accurately in any reasonable amount of time. Either you shoot it 10m away, or you take two minutes to do it.