I tried the seven minute workout for a little while and saw no improvement in any dimension. This[1], on the other hand, has gotten me some significant results so far, five months in. [1] http://stronglifts.com/
I find it hard to believe that you can do squats more than one day a week. It takes a while for large muscles to recover, especially when you're doing heavy weight.
I've had much more trouble consistently increasing weight on bench presses.
In fairness, I probably have a mechanical advantage for squats.