Will,
I race an old wooden Mozzie; it was in my price range at the time had been raced only in a fresh water lake (minimal corrosion and hull stresses) and I didn't know any better. <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />
I'd always raced timber yachts when I was growing up when the difference between timber and fibreglass was like chalk and cheese. You could make the timber yachts light and strong but the fibreglass yachts were heavy and strong. You could easily fix damage to a timber hull and slap on a primer and undercoat but there seemed to be a lot more messing about with fibreglass. From what I remember, the lightweight fibreglass hulls didn't last as long as timber.
Thanks to modern materials (carbon fibre, boron, pre-preg, foam sandwich consruction etc) the composite hulls have come a long long way in terms of strength to weight ratio. Moulding plugs have also improved to get the best out of the Mozzie and taken the buoyancy to the maximum limit of the rules.
Unless you really like working with timber and stripping and re-painting every couple of seasons composite is the way to go. You can probably guess by now that my next Mozzie will be composite. <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />
Regards,
Peter