I have one of their soft shell ski masks rather than the full balaclava. It's great for long runs or sustained activity in an upright position, since it doesn't saturate and become hard to breathe through like a scarf or buff. I don't wear it on the bike anymore though because my riding position makes it hard to adjust comfortably. The material items made of doesn't stretch much, if at all, so to be loose enough to not smash my nose while riding requires it to be almost falling off my face while upright. This varies based on your ridingposition, so your mileage may vary. I've also had some issues with air leaking up around my nose and fogging my goggles, but that's an issue I've not solved with a buff or any other face cover either, so I dunno if I'd count it against the mask.
So all in all, if your rides are long and upright, it's not a bad option.