The controllers is just something you either love or hate, it's not something i could pin down (more than i already have). You either get it, or you don't.
And yeah, i used to play BF2, CoD2, 1942, 2142 and i was pretty decent with a M&K. But there is something to be said with console controllers on FPS's - Just youtube some of the Halo comp videos to see how unreal people can be with them. Again, it all falls into the casual thing, i want my console to work from the box, and everyone to be on a level (and decent) playing field - not who is the most techy/has the most money to spend.
Like i said, my serious gaming is done on PC, and casual on a console - recently i'm becoming a big fan of the wii.
Small hourglass island
Always raining and foggy
Use an umbrella