For what it's worth, I have a sled helmet, a dirt helmet and a street helmet. They are all similar style but for the snow I appreciate lots of room for balaclava and breathing room around my face and must be light, for the dirt, a little tighter and venting around my head and light weight and for the road it is heavier but must be quiet and tighter fit around my goggles.
Sweat the most sledding and this causes fogging of the goggles so that is most important to think about.
Many thanks!!!