I use them for winter climbing (I'm luky and get hot hands), they are nimble enough to play with gear although one pitch is enough and I stick on an outer layer for the belay.
Used them when snowboarding in the alps for a week too. got a little damp by the end of a day probably from small amounts of snow getting in the cuf over the hours I wore them rather than leaking.
Peter, I meant an elastic drawcord. If the cord is loose the material folds/slides down over time. If it's tight then when I take a large step/scrable/etc my trousers pull through then the top of the gaiter is at a lower heigh on my trousers after the step/scramble/etc. I'll experiment a little more if others don't have a problem. Might try attaching some velcro myself.