I have not been able to use this balaclava out on the mountain yet so this review is only about fit and comfort. For your reference, I wear a 7 1/4 in New Era fitted caps.
I compared this one with the SmartWool (Item: SWL0380) and the Outdoor Research Helmetclava (Item: ODR0611).
The SmartWool is the best fitting. Fit is snug with no gaps, but not tight. I didn't go with the SmartWool because this one is best used as an insulator just like their thermal undergarments. In other words, it's best worn underneath an outer layer. Of the three balaclavas, this one is the thinnest and lightest. Wind will go through this one the easiest and this one will get soaked the quickest if exposed to blizzard snow storms.
I didn't go with the Outdoor Research Helmetclava (size M) for a number of reasons. 1) the seam of the mouth/nose section rides up too close to my eyes and pinches some of the skin near the bottom of my eyes which makes it a little uncomfortable. If I pull the mouth/nose section down more, it doesn't fit quite right and will eventually ride back up. The holes for mouth ventilation will work to reduce fogging, but then again these holes will allow for cold air to enter so there's a trade off.
I went with the MH Power Stretch Hardface because this one will work the best for protecting my face against the elements. I also like the hinge system for the lower section of the mask which makes it easy to pull down under my chin while still fully protecting my ears. My one complaint is that the top portiion of the hood is a little loose. It doesn't hug my forehead like the other two, but I'm going to be wearing a beanie or helmet anyway.