I've been using KDE (and now Plasma) for many years, and although I have encountered most of the whizz-bang features described in this article I seldom use most of them with the exception of krunner. I actually consider many of these "advanced" features to be unneccesary and at times a bit annoying, But that is the beauty and elegance of KDE/Plasma: --it is quite intuitive and highly configurable with a complement of features that each individual user may prefer.