I bought two of these, one for myself and one for my husband.  For me, the neck gaiter works okay-- there is considerable space between it and my neck, but I can use my coat collar to tuck it closer if I need to.  My husband, however, tried it on once, and hasn't worn it since... and I'm pretty sure it's because it was a little uncomfortable for him to put on.  He has a very large head, and the gaiter is only moderately stretchy.  It is what it looks like-- a simple tube-- and it has enough body to itself that it somewhat stands up around the neck.  For me, that's fine-- I don't want it to collapse and expose my neck.  Also the space between the gaiter and my neck creates a place that I can use to keep my chin warm, if need be.  It's not big enough to pull up over my nose, though... not unless I want to leave a gap at the base of my neck.  Definitely it's not over-big in any direction!

If I had it to do over again, I might have spent a few dollars more for a more generously-sized product... particularly for my husband.  Then again, if you're watching pennies, as we are, and don't have a really big head... it could be fine.