I paid for Poker Ace because I think it is superior. I used Gametime+ for months before trying PA. Here is why:
1. The stats lay out so much nicer without having to mess with positioning.
2. It automatically finds tables instead of you manually selecting them.
3. It shows the hole cards of mucked hands at showdown so you don't have to view the hands history.

All of these reasons are worth $25 to me - especially if you multitable. Boot it up and just play.