I lost 18 lbs from my first round of P90X and I've lost 17 more since starting a P90X/TurboFire Hybrid eight weeks ago. I have yet to try Insanity. The wife had TurboFire already, so I went with that hybrid instead. I'll probably start another round of P90X in December and follow that up with P90X2 at the end of that round. I still have 15-20 pounds I'd like to lose first. I started at 5'11" and 221.5 pounds and I hit 186.5 lbs this morning. My original goal was 180 before my 40th birthday. I should hit that and surpass it by then. If I can hit the low 170's like I was in college, then I 'll be happy.
My eating is pretty much a matter of a 40-40-20 carb-protein-fat ratio for calories. I use their Shakeology when I want a lower calorie breakfast. The wife loves the stuff. I've been using myfitnesspal to track calories. The P90X diet guide/meal plan is a bit confusing, but if you know how to cook, then you can adapt easily. A clean diet is much more important than the exercise when it comes to weight loss.
Beachbody is starting a new promotion starting November 1st. You can get Insanity, P90X or TurboFire and a 30 day supply of Shakeology for $205, a savings of about $45. You also get 30 days of free membership to Team Beachbody Club and free shipping. I think shipping was $20 when I ordered P90X. If you are looking to lose weight, Shakeology is good since it fills you up with only 250-300 calories based on what you put in it. I'll get more info on the Challenge Packs, so if you want to go that way to save the money, let me know or shoot me a pm.