I have been working with 1/2" Nida Core with a fiberglass skin. I chose that method because the skin is made with a polyester resin. This allows for easy gel coating to match the interior white. Gel coating is a lot more work than painting, but I like it's durability, lack of fading with age and easy repairs. The Nida Core is also 1/3 the weight of plywood.
Nida-Core material
This is a front that came through right before our overnight from Cumberland Island to Charleston. We were well past it, but when the wind started to build, we started to furl in the Code 0. Then a 90 degree shift and winds to 30 knots make you happy that skin grows back. The next one had a warning from the coast guard and that brought winds to 46 knots. We were more prepared and were sailing with a reefed mainsail only. Luckily, they blew through and we had a clear night with steady following winds.