The VholdR sounds like it's well designed. The laser point/level feature is a great idea. Not so impressed with the use of a cmos sensor, but it looks like they've programmed it to lessen other video artifacts. Still a bit heavy for side mounting on a helmet. It would pull the helmet crooked.
I'm impressed that they actually considered that someone might want to use the cam while wearing gloves. (Duh on most other helmet cam designers.) And designed a simple, non-ambiguous action to it.
Not cheap, but not much more than what I wasted on the two Oregon Scientific helmet cams.