I'm with the trying it on and testing lots and lots of helmets.
Something to keep in mind my resident apparel "expert" taught me a while back. When trying on a helmet, make sure to look at yourself in a mirror. If your cheeks are too squished in, it will start to become uncomfortable after about 30 minutes, and probably not break in far enough... Another point to watch out for is your forehead. How snug is the helmet on your forehead, compared with the back of your head, your cheeks, and your chin? They should be equally as comfortable/uncomfortable. Most helmets these days will "grow to your head" about 15% percent, which isn't as much as you think. In most helmets, it's between 1 and 3 millimeters, so envision a penny being pinched between your helmet and your cheek... Also keep in mind, a helmet on the "small" side for your head is safer than on the "larger" side of your head. You should have the helmet on, and vigorously shake your head side to side, and the helmet should not move sideways, more than your skin. Once you stop shaking your head, the helmet should be gripping your face where it was when you first put it on. Not half cocked over an eye or something. If they'll let you, walk around the store admiring other motorcycles, talking to rep, or sitting down and reading a book, for about 10 minutes with a helmet you like, on your head. People look at you weird, but you're about to spend $120 on something you're trusting your life to, and which is responsible for part of your reputation out on the road. Let the people in shop laugh, if they want to..
Personally, I go get a coffee with a straw and go read an article in Motorcyclist. If I try and walk out the store without paying for the helmet, I know it's comfortable enough to forget about, and I buy it (after they catch me

)
www.NewEnough.com is an awesome to get that stuff, once you've found your size....
Hope this helmet, and good luck hunting.