I have the Kuiu 0 degree bag. I've spent some time with it, but certainly need more time to get a complete review of it. But first impressions is I like this bag! I really like the Stunner stretch as I'm a active sleeper and move around a lot and this bag seems to stretch better with me than other bags. Its well made. It compresses down nice with a Kifaru compression sack.
I looked at other bags, including the WM bags, but the Kuiu bags kept coming back on top of the list for a down bag in terms of what I was looking for.
I've got a 17 day high altitude mountain hunt booked in early March and I will be taking this bag. I'm sure after this hunt, I will find any gaps or issues. But so far, I have confidence in taking it and I don't think there will be any issues with it. I think its a keeper.