It is hella hard. I used it in conjunction with my other workouts. My gym had it, so it was free.
To my understanding the program is a ridiculous amount of money, so go with what the others have said with downloading it for free or asking a gym to burn it for you. Also! You need the equipment like a pullup bar, and dumbbells etc.
I thought the exercises got repetitive. The "back and leg" disc is literally all lunges and pull ups.
Yoga/Kenpo (I think it was) was an hour and a half. Not only is it very strenuous, but it is time-consuming. I remember that I was frequently sore the day after, but I would have to do another part of my body to keep up with my own lifting/the program. It's all about how hard you push yourself, the annoying buff guy can only take you so far.
Half the time he just traipses about and supervises the other people. His counting also gets off, which is why I'm glad there is a "silent" option.
Overall, try it out. It's very difficult, but I got more definition.