I much prefer all of my Kuiu clothing pieces to my Sitka stuff. I own plenty of both. The Kuiu attack pants and guide vest are my favorites. I took both to Alaska, along with my REI Kimtah eVent jacket, and all performed admirably.
The Kuiu rain gear is made of an air-permeable membrane fabric, much like eVent, and should breath notably better than anything GoreTex. Several people I trust report great performance from Kuiu raingear. Goretex does not breath, in my experience, and I have tried a bunch of it.
As for comfort, I am curious as to what Kuiu pieces Edelweiss has because comfort is off the charts on the ones I have.
I do really like my Sitka guide gloves and Ascent pants (I have three pairs of those), but the Kuiu Attack is superior in every way to Ascent.