I'll go with JJ. I think he's got more weapons.
Expectations for Janowicz sky-rocketed based on his run to the finals in Paris, but I think people need to remember that this will be his first real season playing tour level competition. He's a talent, but nothing comes easy in today's tennis. He's going to have some ups and downs as he adjusts to the big leagues and the step up in competition. Hard not to like his potential though...huge serve, great touch, moves exceptionally well for a guy his size. Of all the young guys touted as the next slam winners, I think he's got the highest ceiling.