Having recently done a fair amount of work on my upright, I appreciate it's construction so much more. The interplay between bass-bar, soundpost, bridge/top etc. really has given me a new appreciation of acoustic instruments. I'm not so sure of the sound quality you'd get from an acoustic instrument made out of a composite material though. I have heard of aluminum upright basses and there was a company who was (up until recently) active in composite uprights/cellos based out of Cali ..... I guess it really would be a matter of what you want heard/amplified - the top of the instrument or the string resonance itself? I have an Underwood pickup which is great for capturing the natural sound of an instrument. On the other hand, my Fishman is strictly string sound.
"Concert Ready" - yeah, I guess that's all a matter of perception.