His style is very similar to Fed, all around with no obvious weakness. Remember, he's only 20, better than Fed at same age. He's in semi of FO and WMB this year, and now US Open. In some sense, he's more balanced on all surfaces.
Can he beat Fed this time? I think he has 40% chance. Still, I'm happy to see someone challenge Fed, to force Fed raise his level. Fed has been too comfortable on hard surface (except WMB this yr) for the past 2 yrs. :-)