Hi Mari,
I have the power half hour series. It is good, but much less advanced than P90X. I bought P90X first, then realized it was too advanced for me, so bought power half hour.
You get 2 lower body workouts - one focuses on the thighs and the other the buns, although the buns get worked in the thighs workout too. I like both of these - some of the exercises are unusual. They don't require any weights, but you still burn without having to go very high rep. In the thighs one, there is some (boring) cardio mixed in. (I'm not a fan of Tony's cardio.)
The upper body half hour workout cycles chest and back exercises about 4 times, then has cycles of shoulders/biceps/triceps. This is similar to P90X style, but it feels more rushed. You choose to do reps of 8 to 15. If you have an hour, I think it would be better to do the first half of P90X chest/back followed by the first half of shoulders/arms as it is an easier pace allowing you to go heavier. I plan to try this soon...
The warm ups in the strength workouts are very short (just stretching really). I didn't think I would feel warmed up enough but actually find them okay.
I haven't tried the half hour stretch workout yet, but it starts with a 10-minute standing stretch routine, which can you do on it's own, then a further 20 mins of floor stretching.
Lastly, there is a core workout, which I really don't like at all. It is actually a mixture of cardio/kickbox and ab work rather than just focusing on abs. Personally, I prefer Cathe for cardio and abs.
A booklet comes with the series which describes rotations, focusing on lower or upper, or advanced if you want to do 2 workouts per day. I've never yet managed to stick with a rotation though. Also, as much as I like Tony, I think we would fall out if we saw each other every day of the week!
Hope this helps.
Sharon