Seems quite similar to Zen's experience, except it seems to be missing folders (which I admittedly don't use often, but they're sometimes handy to group a Jira ticket with a PR, or similar). I'll probably still stick with Zen while it's around, and maybe I'll hop over to LibreWolf as I'm not too happy about Mozilla's recent stance on privacy.

I found it too buggy in my usage, it just doesn't compare to the polish in Zen or the other forks. Better just to use the horizontal tabs IMO.