I absolutely love my fps pro from mad catz. The ONLY problem I have with it is the quick engage triggers-- the triggers are 'hair triggers' which engage at the beginning of the pull, the problem is there are no trigger stops do you still get (most) of the travel of a normal Xbox pad. This becomes an issue when you're using semi-auto or even fast 3 round burst weapons like the famas or g11 as you have to fully release the trigger to get the next pull! There have been quite a few times in the heat of battle where I've mis-fired and I end up dead because I didn't let the trigger up all the way.
They were the first to come up with the tactical buttons on the rear of the gamepad-- too bad they placed them too high to be useful. I bet mad catz is kicking themselves over the success of the paddles on the scuf controllers. Still, mad catz could yet fix this by just moving them lower or making the buttons themselves longer (oblong) to accommodate larger hands. I have a hard time listing this as a fault as it is an excellent idea that just wasn't executed well. So too, I feel complaining about the crappy D-pad is sort of silly as it's no better or worse than the original controller.
Other than those issues the fps pro is money! The sticks are über responsive and have a bit more radius of travel than the standard pad. They're also silky smooth-- seriously my biggest fear with the scuf controller is I might have a hard time going back to the creaky Xbox sticks. They also have a nice dead zone which is something most 3rd party controllers lack. I love the finish and grip on the controller. As I said before, my hands don't sweat but the fps pro FEELS more expensive in your hand. I never thought that lights on a gamepad was anything but a gimmick to attract children but the stick lights are kinda cool...
Overall it's a better gamepad for fps than the standard controller and at 40 smackers it's hard to complain as it's cheaper than the OEM.