Does it matter?

I have a Bell Slant only because there are idiots out there with moving weapons they ride in.

Looks good, but between mountain and road, your head is a head, and pavement is hard. I find that mountain bike helmets have more side protection, and road has more forehead to nape protection.

I see no problem in using any helmet for any means, have you seen what people used for helmets 50 years ago?

Always wear your helmet if your not going more then a 1/4 mile from home IMO