As a long-time mediocre sax-player, this is pretty interesting. Also, incredibly beautiful work and I would love to play around on it. However, I'm not sure that making the saxophone more logical in terms of fingering results in a better instrument. It's not the possibilities that inspire me when I play saxophone (or these days guitar) but rather the limitations. Each musical key has its own character and there are licks that I will play in G that I won't play in Bb.
Has anyone played one of these? I'd be curious to know how standard jazz saxophone phrases (Parker, Coltrane, etc) feel on this instrument.