I have come to accept the fact that I have a large head, however, I thought that an extra-large size hat would be sufficient. I was wrong. My wife was tickled to see this hat on my head. I can barely force the hat down far enough for the ear flaps to cover my ears and when I do it creates pressure that I can only describe as a medieval torture device. This hat is a very nice quality hat but I would definitely order one size larger than you would normally use. I think I'll save this for a member of my family with a much smaller cranium.
...basically the ear/neck flap is too thin and loose, does not hug your head enough to keep you warm, especially if there is any kind of wind outside...the rest of the cap is fine, but I felt no warmer than when wearing a normal winter hat without an ear/neck flap.
And this is me with an XL head size to begin with, ordered the L/XL size. The hat's headband actually fits me rather tightly. I supposed you could make the argument that Asics designed the flap to be loose on purpose in order to avoid overheating---problem is, if the temperature is say 35 or under, this means your ears and neck will be cold for at least the first 30 minutes of your run before you heat up sufficiently enough. FAIL.
My Land's End Squall hat is dorkier looking, but I will be keeping it in the meantime...its flap is just slightly smaller but thicker and tighter-hugging...when I'm warm enough not to need it, the flap can be easily rolled up and out of the way. Why didn't Asics think of this?
Disappointing, because I've had good experiences with Asics apparel until now and really wanted to like this one too.
UPDATED 2/27/2013: I sent mine back and bought the Asics Men's Thermopolis XP Beanie, Black, All ... light years better in every way! The only downside is that being a Beanie, it does not have a bill which would keep sun, snow, or rain out of my eyes...oh well, that just means I have to wear sunglasses or goggles.