I just don't see Pete being able to make a dent against the top 4 players today. While his serve is better then anyone ever, they do everything else better (movement, defense, FH, BH, return game).
The idea that he'd just check out of rallies to "end points quicker" too play these guys is just silly. If it were that easy, the pros would be doing it overnight. The tour (as a whole) defends too well to just to make that a high % play anymore. In 2013, an in form Sampras is in the "dangerous floater" category category rather then one of the favorites I'm afraid.