I've been doing Tae Bo for about two years, and have mostly mastered the serious cardio workouts (of which Tae Bo II: Get Ripped is the most difficult). I purchased Tae Bo Flex because I wanted a Tae Bo workout that would focus on muscle definition (particularly in my abs) as opposed to cardio endurance. For the most part, Tae Bo Flex delivers.
Tae Bo Flex is different from previous Tae Bo DVDs in that the moves are performed more slowly, allowing the class to concentrate on the desired muscle groups. Additionally, after a certain number of sets, a move - for example, a roundhouse kick - is held, muscles flexed (hence the title of the workout), in order to strengthen specific muscle groups.
In general, each move is performed as follows: two sets of eight normal repetitions, a held position for eight counts, another set of eight normal reps, and then a final round of a flexed pose. Then, on to another move. During the course of Tae Bo Flex, you'll do a number of moves in this manner, including the roundhouse kick, side kick, front kick, back kick, various punches, and some pseudo-speed bag. Most of the concentration is on your lower body, but the workout does include a few positions in which you're flexing your arms as well.
For the most part, I enjoy the workout; it's definitely something different than what I'm used to! However, it isn't nearly as difficult as I thought it would be. The cardio (i.e., the "normal" sets) is relatively light, and I never really work up a sweat. Also, you only hold the flexed position for eight counts - essentially, this only amounts to about eight seconds! - which isn't very challenging. And this is coming from someone who has a very poor sense of balance, mind you! In fact, some of the previous Tae Bo workouts, such as Get Ripped Advanced 1 and 2, feature longer flex times than this. Finally, at just 45 minutes, Tae Bo Flex is about 10 minutes shorter than many other "Advanced" Tae Bo DVDs.
Although I've owned this DVD for about five months, I usually only use it on my "off" days - those mornings when I'm just too beat to work through some of the more advanced Tae Bo videos. Nonetheless, newbies might find Tae Bo Flex helpful. The leisurely pace makes it easier to learn the basic moves, and the flexing does allow you to focus in on your body. You really gain a sense of which exercises work which muscle groups, because you can literally feel them in action. Overall a decent DVD, but I'm going to knock off one star because there really should have been more flexing!