Hi!
I just got P90X and I'm on Day 4, and it is SO MUCH FUN (at least, I think so). Challenging in a very different way than Cathe. The DVDs are good quality, and overall I think it seems like a good value - you get 12 workout DVDs for around $150. All of the DVDs are around an hour in length except the Abs workout, which is 16 minutes.
Definitely do a search and read some of the previous posts. Like a lot of the people on these forums, I plan to tweak P90X a little bit here and there - for example, I previewed CardioX and didn't think I'd like it, so I'll probably substitute a cardio workout of my choice. But overall I'm happy with the workouts and I'm really excited about the next 86 days!
Dee