Ana Caban's Pilates Abs Workout is a humbling experience. Perhaps not for everyone, but for me, definitely. It's intense. It clocks in at 25 minutes and it's challenging for pretty much the entire time. Shot on location in Hawaii, the backdrop is beautiful, but you probably won't notice the scenery much till it's over. As described on the back of the case, it's a "vigorous" workout.
I didn't have a chance to do a search for reviews on this one, but you can find some reviews over at Amazon.