You have an extremely limited movement speed in FPS games so your argument makes no sense.  If you need to move a tiny amount, tap the button.   On the other hand, you can aim as quickly as you want to with a mouse -- you can turn 180 degrees and stop on a pixel if you want, something that is impossible by any measure in Halo 3.

I've not once ran into a situation where I wished movement was more precise in PC gaming.  But whenever I play any FPS game on my 360 precise aiming is simply not an option.  Why do you think halo 3 aims for you?

You come from console gaming, so you probably move to aim.  I see it all of the time even among halo players -- their fine aiming is based on movements rather than actually aiming.  If they're just slightly to the right of someone, they walk tot the left and shoot them rather than aiming to the left.  This is a very weak technique and it would never work against PC gamers who are dodging you with movements while aiming as quickly and accurately as they want.

oh, also up your mouse sensitivity. It helps movement being about to look around faster.

The truth is taht if you get a really good pc player of CoD4 for example and the same for console and put them both to play in the pc and console, the pc guy would only stand a chance in pc, while the console guy could win on both plataforms. That would be because is easier to get to pc gamming than to the console one. There migth be some exceptions, but that would work on 80-90% of the time. The console guy would take 2 or 3 matches to get used to the controls and then would be fair game. The pc guy would get pwned every time he played in the console.

I can perform with a keyboard just fine. If it's a problem problem, get a mouse with more buttons and assign one for your thumb to walk.

I think Half-Life (or Half-Life based games like Counter-Strike) is a good way to get used to the keyboard because of how you move around in the game (not to mention platforming environments).

i rest my case for keyboard + mouse

what are you talking about.  Honestly?

And I think COD4 PC does support USB xbox 360 controller

So you can have a Console player play the PC version (with USB controller) vs PC player.

And I would put all of my money on the PC player.

You're really generalizing here, especially when people who play console games complain that they can't use the keyboard and mouse combo well. 

this is a very good argument

lol, that video kind of helped to support what I said right above you. Can't do that with a controller. 

ya, I dont see a controler player winning in a match against someone at that level.