Wood v. glass
Ellis - The biggest difference that comes to mind is that glass doesn't rot and doesn't require nearly the care & maintenance that a wooden boat does.In light winds & relatively calm seas, the O'Day should sail circles around the wood gaff rigger: in those conditions, you'll think you've moved from a '70's Buick to a Porsche. The O'Day will point higher & go to windward a lot better than the gaff rig BUT, when the wind & sea kicks up you'll probably miss the weight & drive of the heavier wooden boat, and gaff rig will stand up to more wind than the O'Day and the much lighter glass boat will have a much harder time punching to windward thru a chop etc.From a maintenance perspective, even though glass doesn't rot, it isn't totally trouble free. For one thing, your O'Day has a cored deck (fiberglass on each side of a balsa core, probably 1/2" thick) Anywhere a screw, a bolt or any hole has been made thru the deck you'll have a potential for water to seep in and start to rot the balsa core. There's lots of info on this site and elsewhere about dealing with this issue. If your Gaspesian gaff-rigger was solid & well built you'll find it was a lot better sea boat than the O'Day: the two designs were intended for entirely different sailing conditions. If you plan on sailing around the Gaspe & the Gulf of St. Lawrence you'd better learn and respect the limitations of your new boat.