I don't like the time pressure aspects. I feel if you're doing those kind of exercises 1. do them correctly (form) and 2. don't try to do as many as possible in a short time period. It's like a race of exercises.
I don't really get it actually, and everyone I know who has gone to a 'box' has ended up with some kind of upper body injury. If I was doing some kind of workout I wouldn't want to rush it like that, I'd put correct form above everything else as well.