I'm not sure how to respond to this. Really, all I can say is you're wrong because...well, you are. Having preferences is one thing but saying a controller (Prime 3's setup included) is superior to a mouse/keyboard in FPS is pure lunacy. A keyboard and mouse setup is not only ridiculously more accurate and fast, but you have a shitload more buttons to work with...and exactly what is limiting about it?
It may be less comfortable than using a controller sitting on your couch (or even less fun; I find shooting with the Wiimote MUCH more enjoyable than using a mouse), but when I'm playing a competitive online FPS, I want absolute control over the game. Not analog sticks and aim assist.
And yes I'll stop derailing this thread now.