You want a super comfortable controller, too bad it's for the PC. Get a thrustmaster firestorm dual.
What thrustmaster doesn't show you real well is this controller is a decent size, easy to handle. Plus there's those extra buttons where your ring fingers sit. Means more buttons to access while keeping your thumbs on the dual analog.
That's why I don't like the gamecube or xbox controller. You need the extra shoulder buttons to make fps type games not so clunky.
As far as consoles go, the Xbox controller is by far the best one, and that is especially for FPS's.
The dual shock setup keeps the analog sticks in an afterthought position that is NOT at all comfortable for prolonged use.
That being said... The addition of extra shoulder buttons will be most welcome on the Xbox 360, but that was a very minor gripe about the Xbox controller this gen, as far as its usefulness in FPS's go.
I have not seen the Thrustmaster controller you mention, but one controller I found to be extremely nice for FPS's was the FPS Master from Gamester. Its build quality was crappy, its sticks were a bit too loose, but in concept the design is flawless for the genre it was made for. If it hadn't been for the 2 flaws I mentioned, then it would have indeed been a perfect controller for console FPS games.