He plays much smarter now, more intelligent, more versatile, better serve, much better at the net, mentally much tougher, he plays the most important points so well. He knows how to pace himself during the match. Definitely more polished version now. The 2011 version was all about the speed, physical strength and movement.
Current Djokovic and even 2015 Djokovic was driven nuts by big hitters like Wawarinka and Thiem.
Imagine an opponent who hits as big as them and rarely misses but also not only runs down every ball , he is ready to out muscle and out rally for 5 straight hours if need be.
Today's Djokovic will find it really really hard to beat this guy.
This is the hardest I have seen anyone hit yet landing everything in consistently, and despite hitting cover off of the ball ,have a clear cut tactical plan behind it all.
Nobody in history out rallies and out muscles Rafa like this.
Djokovic 2011 might have been a less complete player,true.
But by sheer level of play and fitness, he is beyond Today's version.
Only 2015 compares and I doubt Even that version gets a lot of wins.
Don't mistake me, as a player Djokovic 2015>Djokovic 2011.
But Djokovic 2011 beats 2015 everywhere except WB.