If you're not a helmet wearing person or wanna flame about those that do or do not wear a helmet, please move on.

Otherwise....

I currently wear a Giro helmet. It's a lower end helmet (this I realize), but what do you get by going upwards? Are we talking just aero benefits? or is there a difference in fit or comfortableness? It does appear that the higher end tend to breath more, but how much difference does it make?

i.e. as long as they're certified and quality, does the protection get better or what? Is there a major difference?