That's about the silliest thing I have seen, all year. I find it hard to believe there is really much advantage or call for it, really- it might be good for developing some idea to it's absurd extreme, to illustrate the theoretical principal, but I don't see any practical use. I do NOT want one.
The guitar-side sound hole idea is not really new- it's been kicking around for at least a few years, this time around, and someone who cares to can probably find a reliable reference to it going back decades or maybe even centuries.
A tip of the hat, though, to them keeping the playing simple, so that the guitar's sound, and not the player's technique, is most noticeable. This is not to day the player isn't good- he certainly is, and I applaud his restraint. Impressive technique is too often used to bedazzle the viewer/listener, so that it becomes impossible to really know if something sounds better, or not.
