Helmets & Helmet Suggestions

We have a Giro Monza as a spare at home but I tried this weekend and it's not so vent-y to me. The Atmos looks better but but about 50% more (£123) than a Whisper (£80).

I wonder if there are assumption made about the rider's head positioning when it comes to the road helmets - as in always on the hoods or drops - so ventilation is designed for that. I tend to ride quite upright so I wonder if that is half of the problem.

Aha. From Wired

http://www.wired.com/2014/06/giro-synthe-helmet/

Giro bases this claim on wind tunnel testing results and a formula that factors in 72 different yaw angles for a rider going 25 mph with a 30 degree head angle (the most common head angle whether riding in the hoods or drops).

So those assumptions are made.