Well, the worst disadvantage for XBox and PS2 and some same kind of playing machine is that.
The game pad will never get enough keys to play the First Person Shooting games. Although there are enough keys, it will be too complicated for every individaul to play with his ten fingers because you need fingers to hold the gamead well...NOT ENOUGH FINGERS !! LOL
Racing games..not good too although the famous GT4...the simulation for driving with a wheel is too bad, far worse than in PC. The Wheel for PS2 or XBox are just too slow, the reaction of the wheel by the car is just like playing the NFS with wheel. Using gamepab to play GT4 just like using Keyboard to play NFS...nothing different! Just Worst!! WORST!!