I'm very curious about the Rainsongs and would love to get a chance to play one and try it out. None of the stores around here carry them, though.

Well, if you're ever in central Vermont....

It seems to me that removing all the internal bracing could only help produce a better overall sound..

Yup.

...and the carbon fibre would also make an instrument that is practically indestructible under normal handling conditions...and not vulnerable to humidity and temperature changes.

Double yup.

But would it have the character and subtle overtones of a really good conventional guitar?

Not quite. Just barely not quite. But I think the difference would only be noticeable in a quiet living room, recording studio, or concert hall with excellent acoustics and a perfectly quiet audience. Somehow I don't get to play much in any of those situations.

Peter