XFCE or LXDE anyone? Honest question - If you use XFCE or LXDE or similar minimalistic DEs, are you happy with the choice? or do you feel somethings are missing that are available in KDE, MATE and the likes?
Back when the lightweight desktops were popping up, KDE was considered pretty memory heavy. Thing is, KDE hasn't really kept up with growing RAM sizes as well as Windows has. ;-) So unless you're trying to run a Linux desktop on a potato, I'd say KDE should now be considered pretty lightweight.
Even back in the day KDE pointed out that in real world use they were not as memory heavy because everything depended on the same toolkits that were shared. Meaning your startup memory use was higher, but once you launched the applications/tools you were going to use KDE used less. (this of course depended on which tools you ran, KDE assumed all KDE tools, run a non-kde application and it doesn't work)