One thing with plaster is that with it you can even out walls if your house is very old and the studs are not even. My house, for instance, is an 1800's farmhouse and much of the wood still had the bark on it! When I gutted to re-wire & insulate, I went w/plaster so my walls wouldn't be too wavy. It is however, a much bigger project like Steve said, and you may already have sufficiently true studs. I'm by no means a professional advisor on these matters, just sharing my experience. Good Luck!