Bryce - My short answer is this… The hat is so versatile and performs so well in both the wet and the cold that it will simply become your one and only beanie on the trail. It's done so well over the years that it's now made it to the top of Everest twice, up the PCT, down the AT, had a full river run on the Grand Canyon and it's even been on the Inca Trail. It's gone up routes on Denali, Whitney and Rainier and been on 50mile ultra-marathon runs, long distance bike rides and numerous adventure races.
Personally it's the only hat I take with me as it's replaced my ultralight merino skull cap, my light fleece beanie, my windproof beanie and my heavy fleece/synthetic/wool beanies altogether. Though I am a hat junkie and I do wear lots of hats all the time, not just my own :)
Whether it's hiking in the rain or braving a winter storm the DWR coated material sheds the water and the high loft 900fp goose down simply gives you the warmth you need in the form of a super compressible and ultralight hat. If you got one of my hats I'd guarantee it to become one of your top choices for any backcountry trip you take and probably even what you wear around town. You can't beat this weekends sale at $49.50 a hat and I always take exchanges and would even take your return if it didn't live up to expectations, though I've never had one over the years...
The long detailed answer is this… :)
A common question I always get is: How will this perform in wet rainy conditions?
The Black Rock down beanies perform excellent in wet conditions because of a couple key items. The DWR coating and the high quality 900fp down plus the moisture wicking Dryline headband. The DWR sheds water extremely well and the 900 fill down actually wicks and distributes moisture where it can then evaporate while you wear it and retain loft in the wet.
These hats are just as good if not better than any synthetic hat out there. I'll take my hats running in the rain throughout the winter and will actually get them so totally wet the entire material is wetted out yet they still retain loft and provide more warmth than a synthetic version. You never get that cold wet feel of fleece, the heavy soggy feel of wool or the chilly thin feel of a windproof layer. The headband wicks moisture from the inside and overall the down acts as a moisture transport layer that spreads it out and keeps you warm.
Realistically while on a hike in conditions where it may rain you'll have a rain jacket as well. So for light rain or short heavy rain the hat will easily hold it's own. If conditions turn to a constant downpour then pulling a rain hood over your hat will keep it completely dry and warm while the DWR on the hat will keep any moisture that does make it in away.
In the summer on long backcountry trips I'll even wash my hat in the river and clip it to my bag where it will dry in a matter of an hour or so depending on conditions. The 900 fill is what makes this possible and I believe is key for those ultralight down layers like a hat or down sweater. It's hard to describe the versatility though, but I've got so many customers that have told me this is simply the ONLY hat they ever wear anymore in any conditions that I've even had lots of "synthetic guys" say they've converted to down because of my hat ;)
As for cold conditions the hat will out perform any other beanie on the market. If it's so cold you need a full balaclava then you probably also have on a full down parka and hood. Many of my sub-zero customers like the hat because it layers nicely with jackets and becomes that first layer of protection and wears perfectly under hoods, helmets and other layers like a windpro balaclava. I've also got sub-zero models, 3 season SUL models and double sill coated extra water resistant models giving you something for ever condition.