I used the free version for about 3 days before buying it earlier this week. I can definitely say that it has nearly paid for itself in this short time. I play short handed tables almost exclusively so the comments below are targeted at that.
When playing short-handed the value of making an accurate read goes up. Having the "Game Time Window" along with auto-importing of hand histories while the game is being played lets me know exactly how often players defend their blinds, how often they fold to a flop bet, and other information that before I only was tracking mentally. Using this info