I haven't had the opportunity to make the drive to the big city yet to purchase a sheet of it. I've gotten zero feedback from MC owners. I had read many reports of big fiberglass boats using them with no negative results, however. I've noticed some pre-fab'd makes have little crosscuts in the surface. My guess that is to keep water from becoming trapped between the runners and the hull (I suspect if water could be trapped, the boat would easily slide sideways or, perhaps, its to allow the hull to dry and not blister). I'll probably do the cross cut thing when I do mine...eventually.