Typical biased post from one of the biggest anti-Fed haters around. There are certainly aspects of his game that are extremely under-rated, #1 being his mental game, imo, where he is strongest in the world, as far as I'm concerned.
There are other areas that are over-rated, such as someone claiming his second serve was better than Sampras' 2nd serve (lol), although that was an isolated case and may have been a joke.
He is bitter because Djokovic got spanked by Federer at USO and Nadal at the Olympics.