Nicholas Garciawrote a review of The North Face Summit L4 Softshell Pant - Men's on January 11, 2019
Familiarity: I've used it once or twice and have initial impressions
Fit: Runs small
I've taken these up to Long's Peak and Mt. Audubon in Colorado winter. -20 degree nights. -15F windchill during day, 45 mph winds. All I had on my legs were SmartWool 150 tights and these pants: my legs were never cold and never wet.
Pros: warm, dry, flexible, breathe pretty good, comfortable, good fabric, decent crampon cuff on inner calf, fits over my giant Boreal Kangri boots. Not sure why I'd wear anything else for trad winter climbing in the lower 48.
Cons: wish there was a tougher feeling fabric for the butt (haven't glissaded yet, but worried about that). If you got a big butt like me the yellow color will make your butt feel a little exposed (underwear lines may show) so I went for black, the thigh pockets are a little too tight, never used them, don't even think about fitting a gloved hand in there.
Sizing: They run true to size but I have a skinny waist and big butt and thicker thighs, so the small was perfect for my waist, but needed the medium for my legs and butt. If you're similar shape, save yourself the time. Get medium. The belt will make up for the waist difference, and the bigger size won't be too baggy. Very slim fit still.