Done All Three
I seem to be the only one to have done all three. I was not a huge fan of P90 X, mostly because of all the equipment involved as mentioned earlier, and as someone that has joint and back issues found higher impact movements than on any of the other exercises. I know a lot of friends who like it, especially the yoga portions, though it is very complete in terms of the exercises it offers. Insanity is a calorie burner, though I didn't actually gain muscle mass or much strength. My preference is the Kettleworx with one caveat, as I really did become leaner and I really liked the diet plan the best as well. The problem is that the cardio really wasn't there for me. Another thing that I want to point out is there are different stages to Kettleworx. The initial 6 week three dvd set is ok, but I would suggest the advanced six week set, and to supplement it with the ultimate body collection. That is a 7 day work out plan. I find that when I am working for at least six days a week on the kettleworx I get similar results in terms of 20 minute work outs to the longer insanity work outs. I also feel the need to do running as well, more for the cardio than for the weight loss. I have noticed that some of the users of commented that you "need" multiple kettle bells, I would disagree, and would encourage people to increase the size of weight and try to maintain it throughout the entire workout. I still can't finish the advanced work outs with the 20lbs weight as a former marine that has kept in shape. Also huge time saver as I am very busy and found that on Insanity I really had to section off a large period of time for the work outs with work that was hard to maintain once my rotation was finished that is much easier to manage on this system. I also like the ability to more easily pinpoint exercises and increase and decrease difficulty. The 10 min options were helpful for days when I don't have a lot of time, or only use the basic three part work outs and throw in a particular section of body sculpting in case you don't always want to keep up a 7 day rotation. Just feel like there are a lot more options.