I test flew one homebuilt Easy Raider for BMAA which generated a fraction of the power that it should and kept overheating - I think it was a reconditioned early model Jabiru that probably should have been consigned to a scrapyard. I also know somebody else who had an oil cooler develop a tiny high-pressure leak and spread the underside of the aircraft with oil - rather messily.
Basically I think that the Jabiru is a rather installation dependent engine - get it right and it's stunning, get it wrong and much goes wrong. G-OESY, which was Reality's first Jabiru aircraft simply put the front end of a Jabiru aircraft on it, which worked very well (and saves a lot of mental effort too).
Wood versus composite? Frankly I'm not sure that I could ever tell the difference, but the wooden looks more appropriate and is cheaper.
G