I got one of these last week; honestly, after trying it on, it fit so remarkably well, I wanted it. I know that there are different head shapes and that makes a big difference between helmets. I usually wear an HJC FS3 Large and I also have an RF1100 Shoei Large for colder weather, they fit very nicely. The Bilt Explorer helmet is a Large, and it feels different and better--it just seems to snugly touch all around my head. Hard to explain but I love it as soon as I tried it. The visors seem to work smoothly and are distortion free. I rode the bike 275 miles this weekend with the helmet and I'm really happy with it.
Disclaimer: I actually work at Cycle Gear one day a week and I try on lots of helmets. Don't want to sound like an advertisement, but I am pretty happy with this helmet. I do not make a habit of posting raves about their Bilt products or anything. Most of the Bilt stuff is budget gear, not bad for the price and good value. But the Explorer helmet is really nice. They got this right.