I've tried these on a few clients and on myself with not-so-well results in respect to form when compared with the traditional front squats. I find that the shoulder blades are more protracted than the traditional grips. This, I've seen, leads to poor posture as seen in a rounded back, and I do believe that Mr. Brink himself is showing a rounded back in the video.
I realize most people have a problem with flexibility when doing the tradition clean-style front squats, and I try to work with them on this. Normally, it's not so much wrist flexibility, but external rotation capabilities of the shoulder joint.