David, Matt (an experienced tech) sez he'll see your instrument today. Are you going to have work done on your VibratoSax or just letting him look at it?
It has some issues, but does play as is. I suspect there will be some design changes made before the next batch ships out. Hopefully they will be able to stiffen some of the keywork, which should improve the feel.
I think the more Vibratosax can get these into the hands of players, the better the feedback to improve on what is already a pretty good design. I really hope they do well, as a bass and contrabass would be wonderful