I don't have historic use of kde but I switched to it about a year ago, after a big release, and its been awesome. Very stable for me, allows custom dpi's for each of my monitors, it doesn't break itself like gnome does. I haven't bothered with other DE's since I tried it, not even xfce (old favourite of mine for tablet & low spec pc), kde performs even well on low specs. And highly configurable out of the box. Its the most stable DE I've encountered for daily driving so far.

What was so much better in the old days (besides memory consumption)?