I am one of the fans of Virtua Tennis (3, not 2009, 2009 sucked) who felt it would not hurt to try Top Spin 3 but in honesty I found the gameplay to be mediocre at best. The player models didn't look good and their strokes bear little resemblance to their real-life counterparts. I could live with these flaws, though, if the game weren't so "clunky" as one here described it. The running animation looked ok, but when the players started executing their strokes it was as if they suddenly stopped their previous motion, glided on the ground for a bit until they finished their strokes.
Virtua Tennis 3, on the other hand, was MUCH more fluid and well animated and the players actually looked and hit similar to the way they did in real life. So I went back to Virtua tennis despite it being less realistic.
Later I bumped in to a cheap 2nd hand Top Spin 2 and found it to be much better than Top Spin 3. Despite the limited vareity of animation and player models the game was actually fluid and the career mode was much less boring and repetitive. Slice shots and Topspin shots would actually go out which seemed more realistic to me. I really hoped they could bring the gameplay of Top Spin 2 back with the updated graphics and player animations for Top Spin 4. That would be perfect.