Poker Academy was developed as a direct result of Research into AI conducted by the University of Alberta's comp sci games group. The games group has developed a number of world class game AI (like the world champion checkers player chinook). It was developed a few years ago I think... However, since then there has been massive improvements that have gone into it.
-it uses actual AI unlike wilson. It will model your behaviour after 1000 or so hands and adapt to it.
-you can adjust the behaviour of the AI (both pre and post flop)
-Poker Academy uses a number of AI bots in the program... You can play a variety of different bots which use different AI programs and play differently and most of them are customizable. i.e. if you have a tough time playing against maniacs, you can make the AI behave this way and practice against it
-The limit AI is the strongest although the no limit AI is getting better.
-support for this program is amazing. They're constantly updating and adding features to the program. They also support research into AI to help improve their product.
See
http://www.poki-poker.com/ for more details on it.
It is without any doubt far superior to wilson.
download the demo and see for yourself.