Looks like it could be a ***** getting out of that newfangled contraption if you wear yourself out using it. Other than that it looks like it really strengthens your core. Can't wait to see if it translates on the field. He's probably wondering if it translates in the bedroom. ;-)
I agree that is a great ab movement. Abs get more work when the lower body is the part in motion. This is a more intense version of a hanging leg raise for the lower abs but hits the upper abs too. We used to think situps and crunches were the optimal ab movements, but in recent times that is no longer believed to be the case. I still do a lot of Roman chairs, and yes it hits the abs, but I do it more for my lower back.