I've got a fairly large noggin, wear a 7 1/2" hat and the large fits fine. Snugs up nicely. the BOA system is a nice upgrade but its not perfect. Dual Zone vents are sweet and work well. Goggle integration also works with Smith Goggles.(Go with a pair of goggles from the I/O series). Keeps my head toasty. Never really had the need for a beanie underneath. Vantage is def better than the Variant. I broke the brim off my Variant. Smith's replacement program for broken helmets is pretty sweet. Shattered by old Vantage. I wouldn't say it's the best on the market but I love this helmet.
Ive know two people who broke the brim off the variant helmet in one season. They've fixed the problem with a single piece vantage helmet this year. Ive got a round head and this fit great. The adjustment is easy to make, it vents well, and its very light. Im a fan.
I work for a ski mountain that requires us to wear helmets. I was issued this helmet and have found it to be quite comfortable. I would recommend that if your ears tend to get chilly to wear a skull cap underneath, but other than that, I have had no issues with this product!