I can confirm that the 360 version runs as smoothly as what we are used to on the PS2 versions, ie full 60 FPS glory, so yes if you have a choice 360 would be wiser in this case – but it is worth pointing out that the first Madden game on 360 (Madden 06) came with a lower than average framerate.
The most complete Madden package is still the PS2 version, but Madden 08 has caught up quite a bit and has most of the features of the PS2 version. Some things are missing, there's no radioshow, you cant create-a-fan and worst of all you can't create custom plays. But on the plus side you now get real radio sports reports via integrated ESPN radio and streaming video's from NFL films.
The game plays really well against human opponents, but I've found that the CPU opponent is almost unstoppable – even if you choose the best team in the game and face the worst team, defense is hard in Madden 08. It's really annoying when you chose a play to stop runs up the middle, and then having the computer run up the middle…