I've definitely made huge improvements in all the exercises. In virtually all of them, I was able to do 25-30 percent more repetitions.
Interestingly, I have not dropped any weight yet, but I do feel a lot leaner (and I think I look leaner when I look in the mirror.). I've stuck to the workout schedule pretty closely, so I guess it's the whole lean-muscle-weighs-more-than-cheese-fry-and-Oreos thing.. Or maybe I'm still taking in too many calories (although I think I've been pretty good about that).
It's still a tough program, and I will be glad not do it six times a week when it's over. However, until then, I will try to stick to the program as closely as possible.
For those curious, I think it's harder, overall, than P90X, although I think P90X does put more emphasis on upper body work. Also, Tony Horton is a better instructor than Shawn T (yes, he calls himself Shawn T, so I don't know what his last name is).