mmm well in my opinion the lack of flexibility is what makes Del Po and Berdych not as good as the shorter guys. Djokovic is 6'2=188cm (i am 6'2 as well and i can't move like he does), Ferrer is 5'9=175cm, and...well in my opinion Nole is even better than Ferrer at movement.
Yeah that's true, I find it hard to believe Djokovic is 6"2, on TV he always looks much shorter than that! I'd like to know what sort of movement training he's done to be able to defend like he does, the guys unreal at moving around the court.