Far too difficult to be enjoyable.
The opening few games are quite enjoyable and the new "EVERYTHING is timing" variables do make the game more realistic, something that is certainly not a bad idea. The problem is, there is no balance between this realism and playability.
The problems start when you become a Junior player. You go from playing complete wasters, to guys blasting the ball down the line, lobbing you and generally whupping your arse big style. The leap is just too great. You seriously go from playing run-down dumps, to modern arenas.
The first two Top Spin games were superb. This one takes itself too seriously, which may well hurt the sales of the next venture.