Bob Gabbitaswrote a review of Mountain Hardwear Glacier Guide Down Parka - Men's on February 6, 2017
Familiarity: I've put it through the wringer
Fit: Runs large
Taken it on a couple expeditions and a dozen or so more casual outings. I run on the large side of my size, but just putting it on it's pretty obvious it's built for some heavy layering. It definitely leans towards being an alpine coat, or for the kind of situations where layering is hardly optional.
That said, it's also one of the warmest alpine parkas I've owned, which probably says a lot about my trip history. It's a thick coat but it's not too bulky for its warmth, so it doesn't get in the way much. Also, helmet, etc., everything fits.
In all, 10/10 would recommend