KDE is a complicated piece of software and packaging it is hard sometimes, but I'm using KDE on Debian since Debian 4, and the team handled all process phenomenally.

One of the tricks Debian team does is they first compile the old KDE with newer libraries, then migrate KDE itself, like Intel's Tick Tock. This gives both a performant and issue-free experience as far as I can tell.

Note: I run Debian Testing on my Desktop systems. Servers always run stable.