I've bought Assault a couple of times, kind of meh for me. Within the last several days MusclePharm came out with an Assault 2.0 that i'm yet to try, but am interested in it.
Noxipro is some good poo. I rarely get a pump during my workouts. In my past experiences with C4, N.O. Xplode, assault, etc. I only felt that Beta Alanine tingle. Noxipro actually gave me a pump. See if you can go to your local vitamin store and give it a try.