DH and I did a rotation of Insanity but it was a few years ago now. Never had any desire to do it again. The workouts get tedious, not a lot of variety. I enjoyed the 60 days but that was enough.
I don't think I lost any weight but I did notice increased cardio stamina. I am a runner (one full marathon and 4 half marathons), I like to do interval training. long runs, and tempo runs with my marathon training. So I think Insanity is similar to the type of workouts I've done before so it wasn't something new for my body. Anytime I do so much high impact cardio, I find my appetite increases and I end up eating more than I burn. I love my high impact/endurance cardio (long runs, cardio coach, love MIC
, and Cathe's other old step workouts) but I'm starting to admit to myself that my body actually does better with shorter type workouts like some of Cathe's newer workouts.
DH felt he gained some upper body strength from all the burpee/plank type moves but he felt he lost all he gained fairly quickly after he stopped the Insanity rotation.
Nice for a change though. I've worked out usually 6 days a week for years and I've done many different things marathon training, P90X, Insanity, CLX, STS twice, Cathe monthly rotations, etc. It's good to shock the body and try something new, also keeps boredom to a minimum.