RE: Wood or D-Ram?
Personally, last season I bought a Sonic 95 (wood, of course) and an Evo 83 D-RAM.
I must say the wood construction has an unique feel. It is light (maybe not the lightest) and one perceives a good stiffness when sailing, but it has the ability to damp vibrations due to chop and ripples. I guess that a good full carbon construction could be lighter and even a bit stiffer, but at an higher price and (probably) lesser durability. The idea to use a thicker material (wood) for the outer laminate, using geometric charcteristics instead of mechanical ones, seems to me indeed a good solution.
On the other side, D-RAM feels really tough (Dur-X) but a bit heavy in absolute. Good for wave or bump and jump, if you don't have pro requirements.
For an S-type, I'd go with wood.