Many people keep saying that it is not as strong as plywood even. It actually has more shear stength than plywood, hence why it is so widely used in building houses these days. Joists are made from it, floors and walls are sheeted with it. So why wouldn't it work well in a guitar cab? It is dead like MDF, and it is dirt cheap. I'm wondering because I have a bunch of it kicking around and I want to build a couple cabs out of various materials to experiment with. I was going to build a pine 1x12 open back, plywood closed back 2x12, and maybe an OSB one to mess around with closed/open back. It should at least work for the baffle wouldn't it? The only drawback I see is it is butt ugly so it would NEED tolex.