Definately agree. The TRUE FPS gamers (and the more hardcore gamers in general) are on the PC side. At least for me personally, I just can't get the same amount of quick precision from a controller as I can a keyboard and mouse. I also feel so SLOW all the time using one. I am one of those "twitchy" reflex guys that plays fast paced stuff like Quake Live, Unreal Tournament etc. and I just need to have that quick flick of the wrist :P.
Now, I have seen some really good Halo players, and I must say that I am impressed with the amount of control that they have with it...I on the other hand just suck horribly. Fighting games, and stuff like Gears of War I can hold my own decently enough, but true FPS games on console are just a struggle for me lol.
Console gamers vs PC gamers in an FPS game...will just get slaughtered....like it wouldn't even be remotely fair.