It’s a pretty broad spectrum with the big name brands. Sitka is pretty diverse with western, waterfowl and white tail pieces, Firstlite targets the active mountain hunting crowd and the white tail crowd, Kuiu targets the lightweight backpacking crowd.
I live in the Canada Rockies and have played in them my entire life. I also hunt deer and fish in the plains.
When I started backpack hunting I would use my regular hiking / backpacking clothes. Went through a few brands but as I focussed on performance (could count your life on the stuff, compact and light but functional) I ended up with a lot of smartwool, Patagonia, Arc’teryx & North Face Guide clothes making up my layers.
I was an early adopter of Sitka (The old Mothwing days) because they were the first I heard of technical fabrics I knew worked for me available in camo.
I moved from Sitka to Firstlite for a lot of pieces. When Fusion came out, I really liked the pattern and went in deep. To this day, best merino base layers I’ve used. I have a few of the kiln hoodies, kiln hoodless and a few of the wick / original aerowool shirts still.
I dabbled back and forth between Sitka, Kuiu and Firstlite for insulation and outer layers for a while.
I have Kuiu left for everything but base layers. I like the fit, function and performance of there stuff the best. Having that decision made and settled, I sold off the outerwear and insulation of the other two. I recouped a lot of the money I’d spent, picked up a lot of great deals in the classifieds and went in with enough pieces that I’m covered from winter coyote hunting to fall elk, late fall sheep and anything else I have encountered in between.
The caveat on the Kuiu system is that it’s expensive because while I can stand hunt white tail or ice fish on a lake without a shelter, it’s taken a lot of pieces to get me there.
The same was true with firstlite. While I didn’t have the best experience with durability for rough mountain terrain and extreme weather, I had enough layers and pieces to keep me pretty comfortable and I think with the down additions to the line, they could compete if they manage to get a wind stopper.
Being Canadian, Kuiu was the most costly to get into along with Firstlite. Sitka was the cheapest because it was available in retail locations and could be found on sale quite often.
As much as I am a fan of Kuiu, a lot of that has to do with really active hunting compared to coyotes where you’re still and exposed where here, it’s mid winter, cold and miserable. I think the Sitka white tail set would be my choice there. The Kuiu Gale Force is awesome and seemed warmer to me but more breathable (I’m not a fan of GoreTex) to let moisture out, it’s priced pretty damn high and isn’t really a multi use piece for my style. Bang for your buck on that type of clothing is Sitka, especially on sale.
If you’re elk hunting the hills for 5+ days at a time, I’d look at Firstlite base layers. I like having a lightweight t shirt (wick) along with one fuse hooded and one non. You can mix and match just those 3 for incredible performance. If you like synthetic base layers, I haven’t found much difference between the Sitka and Kuiu. Get yourself a pair of light weight zip off bottoms. Again merino for long hunts, synthetic for short trips.
Synthetic will dry quicker, is more durable but doesn’t perform for temp range and wicking as well as merino does for me. Especially for more than a weekend where the synthetics definitely hold my smell.
Lower outer layers. I prefer the fit and feel of the Kuiu. If I only bought one style, it would be the kutana. With my zip on leggings and moving constantly, they keep me super warm. They’re also slightly DWR coated and I loved them in 30” snow this fall with gaiters over my boots. For sitting I have a pair of puffy pants that I can zip over and offer a ton of warmth. Particularly if I get them on as soon as I stop to retain as much heat as I can. For protecting my puffy pants or in case of weather - rain pants. Best I’ve used for weight / size is either the E vent rain pant from MEC ( who is now anti hunting and they have only super bright colours so I don’t support them anymore) or the Kuiu Kutana stormshell. I have had some arcteryx that keeps right up with the Kuiu and the MEC is a clone of a Patagonia.
Now of them - Arc’teryx, Patagonia and Kuiu all use fabrics, membranes and factories from Toray. E-Vent is also a widely incorporated material that I’ve had luck in, especially boots.
Upper Layers - for insulation - the Kuiu stongfeece or the Kenai ultra get my vote if I’m wearing it while hiking. The strongfleece 260 is bodymapped for wearing a pack and kept me dry in a 3 hour rain shower. I have a few of the peloton 240 pieces I love for an extra layer with this stuff if I need to cut wind to stay warm.
While I’m stopped. - puffy jacket. Mountain hardware or super down ultra early season, super down pro from late September onward.
Axis soft sell or kutana storm shell as an outer layer depending on weather.
Socks - icebreaker merino liners, a few different weights of Darntough socks as a boot sock. (I wear unlined boots year round)
Gloves and beanies - I layer these also. Sometimes with a neck gaiter. I have first lite base layer gloves and beanie, tag cuff beanie if it’s really cold. Kuiu axis gloves for warm but breezy weather, Yukon Pro for colder and winter weather.
If I mix and match a heavy merino base with a thicker fleece mid, puffy insulation and the rain shells over top, I stay pretty damn toasty but that’s a big investment in my clothing system.
I have a mix of camo (mostly the early season gear because of bow seasons) and solids. This allows me to use my layering system year round without it being camo. A lot of the more expensive and late season ( super down pro for example) gear I bought in solids along with pants and wear them daily to get the best bang for my buck out of them.