Oh god, I stopped reading this thread ages ago, but some evil tractor beam has drawn me back.
Maybe part of the issue is not whether it's better to wear a helmet (it is), but rather that helmets don't do their job as well as they should. If one does research on the relative safety of different helmets, one finds precious little information. CU has an article on its web site about children's helmets, but their older work on adult helmets doesn't cover helmet designs presently available and doesn't seem to be available on the web