I've had the 5th Gen X1 Carbon for a while now, its served me well I wouldn't hesitate to recommend it.
X1C6 is a wonderful machine, go for it.
I am using the 5th gen and it's just about the perfect Linux laptop but a while ago I read that the 6th gen needs some tweaks under Linux, https://delta-xi.net/#056 or https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_X1_Carb... for example.
This may have changed since but the 5th gen is probably a safer choice for the less adventurous
My wife, the professor, is finally going to replace her 2011 Macbook Air. She was excited to check out the new 13" MBP. Then she saw the touch bar (without a real escape), hated the keyboard after typing on it in the Apple Store, and realized she'd have to replace the dongles she uses to present to her classes (VGA and HDMI). What really killed it was when she realized she'd have to have yet another dongle to plug in her mouse.
She already has a Linux desktop both at home and at work, and asked me if I'd help her put Linux on a laptop for her. We're looking at the latest X1 Carbon..