Since my plane is an open cockpit biplane, I'd like a decent helmet. My design requirements:
Reasonable protection - think low speed up-and-over. The full harness will keep me from the panel; but it would stink to get a stick through the mellon or a knot on my head at a three foot fall.
Lightweight
Doesn't interfere with vision
Can be used with a normal aviation headset
Cool - I'm in Alabama, and it gets hot here!
Cool - I'd prefer not to look like a dork. A full modern fighter pilot helmet would look dumb coming out of a butt slow WWI replica....