My brother give it to me the other day and I've only used it once. It was at Moncayo, Spain, with minimum temperatures of -2 º C / 28 ºF, wind guts of 80 Km / h or 50 Mi / h and snow storm. It worked fine but I noticed that it's too large for my head, it moved with the strong winds. I have a rather big head (59 cm / 23.25 in) and the size of my balaclava is the regular, so I can conclude that they're manufactured in too big sizes. However it didn't get wet and repeled the moisture well but I felt a little cold when not covering with my hood. In fact the weather conditions where awful and all our clothes were frozen when we went out from the storm.
This is the one I use. My only complaint is that with the Windstopper material I find it very difficult to hear. At times this has presented me with problems. I would buy one a little larger than normal to allow myself to pull the material away from my head to hear when necessary. It does what it says though, no wind flows thru it and it is plenty warm. I'll probably try something else once I wear this one out.
Used on Mount Massive on rather windy and cold day Jan 2005. Plenty of warmth, but so confining that I preferred a thinner stretchable balaclava - even though that left me with frosted nose.
In slightly colder/more windy weather, I would have gone with the windstopper balaclava and in that case be very pleased with it.
With the stretchable balaclava I can vary wear between:
1) folding back up to a hat
2) pull opening below cheek, leaving entire face free
3) Pull opening to just below lips, covering cheek but leaving mouth and nose free
3) Opening only for eyes (covered by goggles) - in which case I have to breathe through fabric.
Windstopper obviously doesnt allow breathing through fabric - which is why there are two openings for respectively mouth and nostrils. However, the main opening is too inflexible to allow the less confining arrangement with face down to cheek free.
Don't know if an as warm but more comfortable balaclava exist, but given that I can imagine such a design this one gets only 3 stars.