You know what the problem is that I have with Raonic? I think he has a solid game and all, with the strong serve and steady baseline game. His serve will win him his service games. And his blunt and somewhat sluggish game is offensive enough to get a break in most sets and otherwise he can just play a tiebreak, which he also does well in because of his serve.
But I just don't see much room for improvement. I feel like.. this is it, you know? This is all we're going to see from him. He isn't going to suddenly change his technique and play like Federer or Djokovic, he will keep his clumsy technique and good serve. What is he going to improve? Serve harder? His movement might be improvable, but he will always keep moving uncomfortably because of his length. Same with Isner and Karlovic.
Nevertheless, he might get some Grand Slams here and there. If he keeps serving great throughout the tournament he might win it. And after the top 4 retires, he has time to win something big.