I just got the Stone Glaciers puffy and posted a review on here yesterday. I don’t wear insulation layers unless I’m sitting glassing or around camp so I like down for being lightweight and packable. I feel like the perfect setup is a lightweight and a mid weight Merino shirt followed by a thin fleece, followed by a down puffy and a waterproof shell.
I used the Kuiu Merino shirts/ followed by a Peloton 240 zip/ now the stone glacier Grumman puffy, and a Kuiu Chugach jacket. That system has worked perfectly for me from the nastiness of November in western wa to the dry cold of Idaho.