Just heard him on BBC2, in an interview. When asked who he would prefer to play, Roger or Rafa? He replied "I find Rafa's game boring and predictable, you know its going to be physical and he will try to wear you down or if your lucky you might just sneak out a win. With Roger its totally different, he comes up with shots you have never seen before and you never know what to expect. so I prefer to play Roger, he is amazing to watch." Ljubcheck also said something along those lines but he said he prefers to play Rafa because he knows what to expect and after a few games you can figure Rafa out. I think its very accurate description of both their games. Federer is a master shotmaker while Nadal is a an amazing counter puncher and fighter.