if you can get them for free or have money to burn, sure, any exercise regimen is better than none. But if your tight on cash the $200-300 that your going to spend on p90X would be more than enough to sign up to a proper gym for a year or two and get real one-on-one training.
If you have no fitness base, insanity could land your ass in the hospital. All those high intensity moves could snap a ligament if you don't use proper form.
Doesn't it just use your own body weight? I don't recall seeing anything ridiculous in the ad. I always hated these workout programs. Great if you're trying to cut fat and have a decent strength base to begin with. If you sit around at 6% body fat naturally and your own body weight doesn't offer a lot of resistance they suck.
i just talked to a coworker today who did insanity. Good if you want to loose weight and slim down. bad if your trying to get ripped or build muscle. you end up needing to eat 25 meals a day to make up for all the calories you burn.