[nerd_dad]

MDF is unnecessarily heavy and tends to soak up moisture. It also tends to creep under load.

It's definitely cheap, but unless you need its good qualities (dimensional accuracy, sound absorption, isotropic properties), I'd stay away from it. Plywood is much, much better, especially the expensive kind made from Baltic/Russian birch (often sold in 5'x5' boards) or maple (ApplePly, a trademarked name).