Wow! Didn't expect all that response. Looked like I offended some folks, tickled others, and just annoyed the hell out of catspaw. What the heck, here's round two of my unabashed opinions:

Rosewood has a ringing, bell-like tone; very powerful. While you have to sort of admire the powerful ringing of it, it lacks in warmth and mellowness.

Maple is sort of a smoother, slightly subdued rosewood. It has a consistency of tone, and balance from top to bottom that perhaps rosewood lacks.

Mahogany has a warmth, brightness and mellowness that I personally love, and sufficient volume for my moderate volume finger-picking style.

Koa I would describe as somewhere between Maple and Mahogany. It has smoothness and balance like Maple, though not nearly as much ring, and it has a subdued warmth. Very nice, intriguing (sp?) tone, but I prefer Mahogany.

Walnut is a lot like Mahogany, but I feel it's a little less warm, a little less bright. Very solid sound though.

More? What the heck, I'm bold, brave, undaunted and utterly foolish enough to utter my little squeaks here among the tall trees. Here goes:

Big bodied guitars kick butt with their huge sound, but for my money, the smaller body has a presence and clarity the big fella can't touch.

By the way, thanks Rick Fielding for the virus warning. I've hired the best consultant money can buy to innoculate my computer to at least hopefully minimize the damage.

Gordon