Update: The battery in this machine started swelling/exploding at 1.25 years, do not order one!

So I finally got a replacement for the old laptop, which works, but is winding up out-of-RAM basically all the time. This time, instead of going for the cheap inspirons I decided to plunk for a higher-end machine that includes a discreet nVidia card. Installing Ubuntu on it was... not particularly fun. All of the instructions say to disable secure boot, then disable the RAID array, then go and install, setting a kernel parameter as you go. Problem is that with secure boot *off* the EFI bios doesn't easily let you set that kernel parameter (at least, it doesn't boot to grub, so I don't know how to do it). And without that being set, you wind up with freezes/crashes that make the install process... rather frustrating. Worse, when/if you do get through it far enough to do disk partitioning you'll get a cryptic warning that your current format means you should create a 1MB boot-like partition... you shouldn't... so back out of that install and go back to the BIOS.

So, you leave secure boot enabled, tell the bios to boot from your USB key. Add the parameter in GRUB, resize the big NTFS disk in kparted, then do all the other little bits to get the other hardware running. Open Source driver was unusably slow even with simple things like resizing windows, proprietary nVidia is working fine so far, but I haven't stressed it. There's quite a lot of fiddling to get HiDPI working nicely (e.g. needing to manually specify flags for Chromium, setting display scaling, setting font scaling, resizing plasma's default panels etc).