No offense to people who write articles such as that (since maybe some people are obsessed about just how little RAM they need to use), but focusing on RAM use of a DE doesn't interest me. I've noticed that some DEs need maybe 200 MB more RAM than some of the "lightest" ones. That's not even worth thinking about in a machine with 16 GB RAM of current specs.
What I'm concerned with is how the DE performs especially with a DAW running. I tried Kubuntu and as nice as it seemed, with some Reaper test projects it was clearly not as efficient in some way since I got xruns a lot more easily (than with other distros with "lighter" DEs). It could be something else about Kubuntu that caused this, but I didn't notice anything running which could be the cause (and I set it up the same way as other distros, preparing it for DAW use). Who knows, it could come down to a buggy driver which by now is fixed.
I also noticed a few quirks which made me wonder if the DE or WM didn't have some bugs (notifications about things crashing like Panel for instance).
It's been a few months since I tried Kubuntu...now I want to try it again to see if that's gotten better.
(edit) I just tried KDE Plasma in Lubuntu as monty did in the first post of the thread, since it only took a few minutes to switch it over. It's not as efficient as Lxqt when running my "stress test" projects in Reaper (more xruns when using high CPU, can't keep latency as low in those situations)...I guess unless I turn off *everything* for KDE effects (and I already turned off most stuff). I don't see much advantage over Lxqt in that case especially since I find Lxqt with Compton seems to work a bit better for me (whem moving windows around quickly it seems really smooth, and presumably it'd be better to avoid screen tear etc.) I guess if KDE gives you an advantage over Lxqt it'd be worth doing, but I can't think of any for my needs.