I have used one that had the wood/whatever shaft and it played kinda ok. My biggest problem with the composite shafts are that they get tacky whereas with a wood shaft you can keep it smooth as glass. Also I think the feedback from a wood shaft is far superior to anything else out there.
I played with one that belonged to a friend of mine. It had the composite shaft. Played worse than a Cuetec w/SST shaft imo (course, I'm not much of a fan of Cuetec SST shafts either).
I was always wondering how an upper-end Scorpion cue would play, iow, one with a nice maple shaft (as in one that JA would use ).