I tried it and I have to admit it kicked my ass after two weeks. P90X is seriously intense. Anyone who can keep up with it will defiantly end up movie-star-ripped after the 90 days.
Elsewhere, the two week mark is probably the biggest "hump" in the program. Before that point you'll just be sore as hell, but after that, your body is asking you "what exactly is going on here?"
I'm not even doing pull ups yet--I've been so heavy and lacked the upper body strength to make up for it. So I replace all the pull up routines with the bands. Someday I'll start the pull-ups, but it's not a priority.