I completely agree. I had the W510, and now have a P50. Both have run Linux perfectly. The only things that may not work (I don't use) are the Screen Color Calibration sensor and the Fingerprint Reader. I got them working on the W510, but never used them, and haven't tried either on the P50.
Work gave me a X1 Carbon 4th Generation, and everything is perfect on it (although, again, haven't tried out the fingerprint reader).
In general, if you can get Atheros or Intel wireless, it should just work out of the box. Those two are the best when it comes to Linux driver support.
Depending on your use case, these are both solid options. I use the P50 for dev work. I chose it because I have 2 2.5" ssds in it (plenty of storage) and 64GB ram (I am constantly compiling android, so outdir in ramdisk saves me hours a day in build time). It can also be configured with 1 2.5" ssd and 2 NVMe/M.2 drives, although the cost of those is still out of my reach.
The X1 on the other hand is great for on the go use. I can usually go a day or two between charges (but I mostly just use it to listen to music and e-mail/ssh into a bigger box to do work).