I bought the YBB "Goddess Package" and love the workouts, in spite of their silly name. They're a supplement to regular cardio/weights for me, or good for an easier day. That doesn't mean all the workouts are easy, just that you feel invigorated rather than drained when you're done! It helps if you've done yoga before - the moves flow well but aren't explained, so if you're not familiar with your hand and foot placement in, say, down dog, you'll flounder a little.
There are a few reviews of YBB on the Video Fitness forum. Also, Buyer Beware with Beachbody - their customer service can be appalling (again, check out the Vendor Reviews at VF for some feedback).
Allison