Which version of KDE are you talking about? Past disappointments with an early version of very unstable KDE 4? Or disappointments with _any_ version of KDE 5 (or whatever they call it)? KDE 5 is one example of a flat-inspired design, with hard to distinguish monochrome icons (extremely stupid), and countless idiotic decisions. For some "traditional" features, you must now use the thing called "Activity", which I never figured out (it's easier to compile your own kernel, really, that says it all). I managed to stay on KDE 4, for the time being.
Confused about KDE? Try GNOME 3! I gave it a try, and binned it relatively quickly. Eventually, the developers of GNOME decided that what makes a desktop UX as we commonly know it must be completely stripped from the gtk library, enforcing people to have a program looking like a phone app. Unsurprisingly, I heard that gtk does not have the following it used to have. There seems to be a convergence toward qt.
Insanity just about everywhere.