I've owned and used both the Dell Precision M3800 and now the Precision 5510 running Ubuntu. They've generally worked well for me. The M3800 with UHD screen and discrete graphics generally sounded like a jet taking off when the fan was going. The 5510 is practically silent in my experience and works more reliably to boot (e.g. I have a lot less trouble with the new Intel WiFi card than I did with the M3800's Broadcom card). Your mileage may vary of course.

I recently got the Precision 5500, which is great for the most part. The screen flicker is a trifle irritating, but I've had zero Linux compatibility problems. (I opted for Intel graphics.)

I just got one with the discrete graphics, and it works great with nvidia-prime. I only had to configure the touchpad a bit to avoid bumping it while I type. I upgraded from my beloved T420, and this is a great laptop.