Quite good -- especially for the price. The AI is purdee adequate, albeit does not exactly simulate human behavior. It does make for competitive play, however.
In using the current version, I find that if I login to the online game site via the game, that I can't quit PokerTH from the menu, but must force quit it (this while just in the lobby, i.e. not in the middle of a game). This strikes me a s bug.