Earlier quoted context omitted.
I was in the exact same situation late last year, and I went with a X1 Carbon 6th Generation. It has been fantastic. Everything just works, and it has probably the best keyboard I have ever used on a laptop
Just 2 days ago, I spent 2 hours researching alternatives for my mid-2012 MBPr 15 and had settled on an X1 Carbon as well. How's the trackpad? How's sleep mode if you use it with Linux? I'm still on the fence, but I ordered an iFixit battery replacement kit for the MBP. After almost 7 years (!), it still has everything I need except for the fact that it randomly shuts down when the battery is at 60%...
Cost me 330 euros from eBay. Pretty good computer for development, but it only has 8gb of RAM.
Nevertheless the 2015 Carbon X1 runs Manjaro Linux with KDE very well, everything works out of the box.
More developers really should consider moving away from MacOS and "fashion" technology, and start recycling older systems. A web developer does not need the fastest most expensive device on the market. Especially not a $5000 MacBook with a bullshit touchbar.