I have done both P90X and Insanity ( crazy right?)
During P90X, I saw alot of weight drop and muscle development, especially in my upper body. I really felt good!
Insanity has imporoved my over fitness and made my core and legs very strong
I am not all the way there yet, but I keep working at it and over time I will get to my goal weight and physical fitness level I want to acheive.
Just keep trying, do a little more each time you workout and you will see results, don't judge yourself by the people in the video, judge your improvement by what you couldn't do last week