By the numbers I'd go for System 76 again, but if the chassis isn't any better these days I'd probably go back to Lenovo.
Admittedly, I use a Thinkpad t430 and a MacBook Air myself, but if I didn't have more laptops than I knew what to do with, I'd be considering Thinkpenguin (though, I'm of the same mind as Linus Torvalds, http://www.cultofmac.com/162823/linux-creator-linus-torvalds... , so I'd be likely to get a refurb'd MacBook Air).
Edit: link to Thinkpenguin site: https://www.thinkpenguin.com/
They are getting very close. I work in very quiet environments and I hate fan noise. Also no moving parts!
I installed some backport which seems to turn off/on at times.
I don't think there are decent brands for linux, or it might require deeper pockets. That's the cost of not working with microsoft.