It's on neither's racquet because neither is an especially aggressive player, although both have big weapons. Djokovic used to be aggressive (going for winners early in a point) in 2007/8. Since then he has basically been an aggressive grinder, rather like Ferrer with a backhand.
This, I used to enjoy Djokovic's game a lot more before, it was more fluid, more technical and looking to take the initiative of the points much more: 2008 AO, 2010 US open SF were some of my favorites matches from him. Recently, he has basically managed to take out all of the risks off his game relying on running all the balls down. Murray is similar the only difference is that he varies shots more. But his main mindset is the same.
Anyway, you would need to pay me to watch the whole match of 4 hours + of them. The way they approach their matches is basically like an Iron man competition, let's keep the ball relatively high and safe with minimum risk and see who is the more macho man in running down more balls and playing better defense for longer. Winners and shot making are nearly meaningless, is all about stamina. I just tune in in the last 20 minutes of the match, where 8 out 10 times Djokovic takes it, due to having a better mentality. Oh and just to add, Nadal wasn't any better, he and Djokovic started this trend of Incredible Physical matches before Murray was a protagonist.
The only thing I give to Nadal some slack, is that he does tries his best to play aggressively with his game, the thing is the way his game is built FH, serve is very hard for him to play a straight aggressive game on faster surfaces. On clay you can see him running over guys whenever he can.