He's overrated, in my opinion, but there's no doubt he has the talent there and was once excellent.
But now he's turned into a 'Gareth Barry' - signed on reputation, not current form/skill. I don't see why West Ham signed him, for so much (I think it was £1m for 6 months loan) and yet he failed to impress. I watched the Chelsea game, in which he had a few chances (one of them was easy) but he missed them all.
Good luck to him though, maybe the MLS will bring out the best of him.
P.S. You just have to look at his brilliant international goal ratio to see how good he can be.