Have not used either but my experience with windstopper is mixed. This was first generation gear from a couple of makers so may be better now. Wind stopper is warm some times too warm definitely want the pit zips. For me a separate rain/wind shell is more versatile. Windstopper can add noise not really too bad but unacceptable for stalking and bow hunting it gets worse the colder it gets. Wind stopper seems like GoreTex in that the colder it gets the less it breathes so again venting or separate shell is best. Like goretex if you will be doing anything strenuous you will sweat.

This has only happened to me with goretex as I have not worn the wind stopper in extreme cold but in single digit temps and lower it is possible for ice to form on the inside of any membrane. This was while cross country skiing at minus 52 so pretty darn extreme temp and exercise level.

See if you can handle the items to see if any of the above are still an issue.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli