I see this informercial constantly, and I was just wondering how its been working for anyone who's doing it.

Started phase this just this week. I will be blogging about my P90x experience on here shortly, but let's just say it has changed my life in more ways than one....."I hate it....but I love it".....

OH MY GOSH IT IS SOOOOOOOOOOOOOO WORTH every penny! I can't tell you how wonderful it is for the mind, body and soul. Tony Horton is incredible and he is obviously doing something right because he is 50 friggin years old! Look at him!!

I think it depends on what you are after. I've seen the workouts and I believe that they would be effective at strenth training and assisting fat loss, but I do not think that it is a mass building program.

I say "assisting" because the real factor for fat loss or mass building is your diet.

Question to someone using it: is it something similar to the Zone 30/30/40 (a very efffective diet IMO)?

It's a great program from what I have seen. There are a couple of annoyances, such as the crossed forearms to make an "X". Slightly retarded, IMO. My big problem has nothing to do with P90X, but with the MLM thing that they have going on with the Beach Body Club. I'd love to sell the program on my site, but want nada to do with any MLM. Been bit by that snake before... but I digress. :)

I just finished the lean version of P90X. Got AWESOME results....lost 13 total body inches and 14% body fat. I would say it really works. I wasn't looking to bulk up though....I wanted lean muscle and I most definitely gained that. :)