A couple of points:
1) Before you changed the serve controls, I was able to serve topspin or slice serves by using the alternate strikes option. Now I have to use the standard up/down + direction and I've always found that method clunky. Could you allow us to set individual controls for putting topspin, slice and twist on serves?
2) I agree with NeNa that you nerfed the slice a bit too much. The only problem I had with the slice before was those 78 mph shoulder height ones, but since the patch they seem weak again. Slice mastery makes slices a bit more consistent, but it isn't particularly noticable. I think the best solution would be to beef up the slice mastery talent for those that want a great slice with more consistency, depth and pace on it, and leave the current slice the way it is. It would allow us to model different types of players better too, like Feliciano Lopez who has an awful topspin backhand and a fantastic slice.
Edit: Speaking of the slice, I didn't really want to mention this because you're working on the AI at the moment, but the AI doesn't use the slice backhand nearly enough, especially players with one-handed backhands. Federer who's known IRL for mixing slice and topspin backhands up quite a bit, basically never uses it in game. I also very rarely see volleyers chip-and-charge.