Agreed. Hands on and practice, practice, practice. I have available to me other students to watch me and of course my Instructor. I'm not saying that seeing what I'm doing wrong would not help, heck it has helped many other atheletes and such, but at my level this would just be a lot of flash and I don't have the cash to care. (nice rhyme, eh?
I think with top athletes they have a talent that many of us will never see. Sure they can learn like everybody else but something in their genetics just makes them that much better or they find things easier. They will get this stuff especially with the right coaching. They will figure things out themselves. Something like this may be an aid but I honestly don't think it will go too far in the development of the majority ... I'd say it may help less then 1%, but that is my opinion that may not be shared by others.