I've heard of it, and I'm familiar with a lot of the Beachbody programs, as well as some other fitness/workout DVD programs. I'm happy with the Beachbody company, and I think people get what the ads say they'll get, provided they follow the program. The company offers support online, as well, which is nice for people who are "support-inclined". The products I've received are high quality (Turbo Jam, Hip Hop Abs, Rockin' Body). The company also offers (for a small price) a way to insure your DVD's so they'll be replaced if they get damaged. I didn't buy that. I figure I'd just replace them.
I, personally, wouldn't get the P90X program for myself because it looks, to me, like a "heavier duty" program than the "dancier" programs. Even though some of the TurboJam and Hip Hop workouts have some floor work, you can do most of the program without involving the floor. So, I'm not someone who wants to do the "heavier duty"/"man" kind of working out. That's just me, though.
I think these programs do tend to be worth the price; although if someone couldn't spring for them, there are lots of individual workout DVD's that, if the right ones were bought, could be pretty effective. Beachbody offers the money-back guarantee (30 days, I think), and I think people need to make sure the company has the thing back within 30 days (and ask about what dates, exactly, make-up the 30 days). I like having the whole-program sets, and I thought the price was reasonable enough - but again, that's me.