I say the same Maxy and Sam250. One of the biggest advantages of this game is the possibility of modding (or mod, I dont know how to say it, sorry). This means you can always have updated the ATP players, the courts, the rackets... simply wonderful.
Secondly, I played PC games with amazing graphics, like Virtua Tennis 2009, Top Spin, etc, but in my opinion these games are not realistic, at least for real tennis players. We know what an amazing point or game is, and it is only possible with Tennis Elbow 2011. In addition to, I like the cameras, fully personalized, the sounds (the grunts are very realistic, for example).
In summary: I bought Tennis Elbow 2011 because for me is the most realistic game I have ever played. Simply very very realistic. The play system is like real life tennis.