I actually like Nadal's backhand. When he's playing well and aggressive it's such a powerful and heavy shot, but when he's playing badly and gets pushed back (e.g. by Djokovic) then he suddenly can't hit it over the service line anymore. So yeah, I agree with MN's 7 overall.
Novak Djokovic:
First Serve: 8/10
Second Serve: 9/10
Speed: 7/10
Mental Strength: 9/10
Forehand: 9/10
Backhand: 10/10
Footwork: 9/10
Volleys: 8/10
OH 3/10
ROS 10/10
Funny how even you have to give him such a low rating on the overhead. The funny thing is, I've been watching many highlights of tennis matches lately and I didn't see Djokovic mess up a single overhead in all of them. I saw him hit like 10 OH winners in a row. But for some reason when I see him in a live match, I cringe every time he tries to go for one and he does mess it up a lot.
By the way, I'd give him at least an 8 (probably more) for speed, right? The guy moves bloody well.
Federer (currently):
First serve: 8.5/10
Second serve: 8.5/10
Speed: 7.5/10
Mental strength: 7/10
Forehand: 9/10
Backhand: 6.5/10 (for Big 3 standards)
Backhand slice: 9/10 (but it was a freaking 10 in his prime)
Footwork: 9/10
Volleys: 8.5/10
Overhead: 9.5/10
ROS: 8/10