Yeah I do find his tennis boring, at least against the non-big players. I mean, it's definitely good, solid tennis, but it's almost always unspectacular. Fed, Nadal, even Murray can play spectacular shots, be creative in their point construction etc. Djokovic is always solid and reliable, but it comes across as a robotic style of play for me. However, his style is a bit more enjoyable when he's aggressive with it, and his tennis is fun against Fed as the two match up very well. Against Murray it's a complete borefest, and it's the same against Nadal, which is saved by the fact that Nadal's forehand is a lot of fun to watch. Against the field, I prefer the other three and many others.