The word minimal often means minimalistic in appearance and resource use, what I want is minimal work. That's why I run default gnome.
Default KDE does more out of the box, and is very usable. Resource usage seems OK. I recommend it over Gnome. The only thing I liked about Gnome was the appearance, which was something purely superficial. (I don't use Linux anymore.)
Regardless, I think once KDE is set up to one's workflow properly, it stays out of the way and can remain out of the way on new systems by transferring the config files. It just may take a lot of upfront work to get to that point and you can get easily distracted tweaking the minutiae over time. For that particular reason, I also prefer just using vanilla GNOME (with only the AppIndicator extension for DropBox and Steam tray icons). Granted, that's a "me problem" because I get easily distracted and can never stick with a specific setup when there's so many options available for me to tweak.
TL;DR: Both KDE and GNOME can be minimal, but the latter requires "minimal work" because it's minimal out-of-the-box and there's not much work that can be done.