biggest thing i don't like about it is how the physioball is a bit unpredictable, depending on how you land, as seen by that rep where you fly off to the side.. If you used a vest, you could come up with some cleaner variations, i'm pretty sure of it.. having your arms counter balance while wearing a vest, you could do some things like REA sldl, REA "pistol", russian jumps etc.
i think something like that would be real effective with a weighted vest etc, only problem is you need a partner.
peace man