Not to say he sucks, but it seems to me that he can beat the mugs easily but when it comes to the big boys, he can't get it done.
Since he won Rome, he's lost four times to Nadal, twice to Murray, and just in the semis vs. Federer.
Is he a notch below?
Perhaps he has less of the extra factors but his mental strength has seen him ascend and make more of his talent than Murray thus far, who is still without a major. Right now he is probably the 4th best player in the world but i expect him to come out with fire in his belly in the upcoming TMS events.