I bought an X1 Carbon 6th Generation laptop (highest specs) from Lenovo because I wanted to put *BSD on it. Started with FreeBSD and now settled on OpenBSD.
See here (aff.)
NOTE: Lenovo's ordering and shipping experience is the worst I've ever experienced.
It took over a month to ship and their forum is filled with complaints (I was lucky to receive mine in fact). I recommend ordering from the link above (Amazon) to save time and uncertainty.
The laptop works almost flawlessly on OpenBSD out of the box. A few minor performance tweaks go a long way.
On FreeBSD, you'll need
acpi_ibm for the function keys.
Nipple and trackpad are perfect with synaptics.
The usual things that don't work (currently): bluetooth and fingerprint.