Fans see the over-the-top chest beating, his rivals hate the incessant bouncing of the ball before each and every serve and he has riled some peers with those imitations.
But Australian Open finalist Novak Djokovic - or the "Djoker" to those who don't know him particularly well - is a young man full of substance and class.
Just ask the 50 under-privileged Kosovo-Serb children his family invited to be courtside in Belgrade for Serbia's Davis Cup World Gorup playoff win over Australia in 2007.
A humble lot, Djokovic's parents have flipped pancakes and baked pizzas in the Serbian mountains for the past 15 years and now their talented son is turning the tennis history book on its head.
Three years after shocking the sporting world in Melbourne with a straight-sets Open semifinal defeat of Roger Federer, Djokovic has done it again to be on the brink of a second Grand Slam crown.
Only this time Federer - with four titles from his past five tournaments - was supposed to be back to his best. Unlike the ailing model of 2008.
This time Djokovic is new and improved, on court and off.
"There is a difference," the 23-year-old world No 3 said as he savoured his 7-6 (7-3), 7-5, 6-3 victory that placed him alongside Rafael Nadal as the only players to have conquered Federer in successive Grand Slam encounters.
"I'm three years older and I'm a more experienced player on the court. Physically, I'm stronger. I definitely feel like that.
"Back then, I was a 20-year-old kid hitting as hard as he can with closed eyes and everything was going in. It was great. Felt great.
"Then, over the years, I faced some situations that I never faced before - pressure of defending Grand Slams and things like that. You grow up."
Djokovic has never before prepared so well for a slam. He had just two weeks off between leading Serbia to Davis Cup glory over France and returning to training on December 22.
"Maybe it helped him that after Davis Cup that he got a lot of motivation," said mentor Marian Vajda.
"Maybe not having much of a break helped keep him in shape. He didn't lose the muscles, all the fitness, the mental strength."