I'm currently trying to decide between a set of LineX coated plywood 15/6/1's (Ron Anchak's), which, if my experience with my own LineX coated cabs is any indication, will be able to be dropped off the side of a building without much harm, and a set of composites, which are very close in price, but which are probably 20 lbs lighter per cabinet. I would imagine that you give up a bit of impact strength in the center of panels of those particular builds, but I know how strong composites can be. I helped build both a LongEZE (Burt Rutan's revolutionary foam and fiberglass airplane) and a Lancair (very fast piston single-engine, largely carbon fiber). Some of those parts are astonishingly light. I don't really expect a structural problem with them at all.