I think you're being overly harsh. The op did say "or models like them", which kind of opens the door to other suggestions.
I guess lenovo's X1 Carbons would be a direct competitor to the XPS-13.

I would not recommend dell, their customer service is atrocious, even their technicians hate it. However I only have experience with a dell xps 730 desktop. The only distro it would run was opensuse...

I have a dell inspiron 1545 and works nicely with slackware. I have no issues whatsoever. You may want to add i8kutils from slackbuilds. Would need to check the wireless card in it, but I've used booth the b43 & sta wireless drivers successfully.

I've owned a few Dells and never needed to contact their customer service (it's not likely they could do much with custom Linux installs unless there were hardware failures). The laptops opened easily enough when I crack them open to clean them out (I usually do that every year or so to clear out the dust bunnies and keep it running cool and quiet). It was certainly much easier than my Asus.

I guess it depends on what you plan, but I buy stuff not ever intending to contact customer service, so even if they have a bad rap, it doesn't affect my purchase. (If there does end up being a hardware failure, I know that I'm insistent enough that even bad customer service won't detract from me getting the hardware replaced -- assuming its still within warranty.)

I contacted them because it was that the motherboard failed (Repeatedly) and the only way to get a replacement was through dell (Proprietary)... Getting them to agree that I didn't need any software help alone was hard enough, that is not even mentioning how difficult it was to actual reach one of their overseas support staff or trying to understand them. And even then the way the case was designed was non-standard and even their paid technicians who came in person couldn't do it easily (At least they were nice).

Eventually I just replaced everything but the monitor...

I have got Dell Vostro 5470 and there were Fedora and Slackware on it. Everything works fine with Fedora 20/21/22 but after fresh install of Slackware 14.1 I spent about day or two to enable Wi-Fi network (backports-3.12.8-1). Now it works but out of the box it wasn't.

Unfortunately, that seems pretty common with almost all OEMs. Actually, pretty much all tech support assumes the problem is software related unless proven otherwise. As a technically minded person, it's especially frustrating to deal with these companies that require their techs to run through scripts and then escalate to a (hopefully) better tech in tier 2 or 3 who might be better to help fix your problem. But, when you consider the chance of getting Joe Schmo who doesn't know a thing about computers vs someone who is extremely knowledgeable and knows exactly what the problem is, it's not surprising to see their support acting the way it does.

It reminds me of this classic xkcd (that I only wish were true)...

I have had 4 dell laptops over the last 13 years and a sager. With almost every Dell I had, the motherboard had to be replaced... the latitude line D6XXX, D8XXX, the E6XXX has been ok. Having said that I will also say they have been the most durable laptops, having dropped, scuffed, etc... they keep right on cranking! No issues with Slackware either. Maybe I just had the luck to get the ones with bad motherboards, but after the replacement... no down time.

The Sager runs well on Slackware too.

Necromancing this thread to seek updates -- has anyone had trouble getting Slackware 14.2 working on Dell's Precision line of laptops? I'm looking hard at the 7720 to replace my Lenovo T530.