Last time I used KUbuntu it was pretty much horrible. (E.g. only 6 month maintained and after that the repo did go offline so my installed system was broken (couldn't even install old pkgs from the DVD because of dependencies)). But the config tools from SuSE where also horrible (convoluted and so slow!), so I use the Fedora KDE spin now.
Having used both zypper and apt-get, I find the latter very lacking, even when coupled with other tools.
Take `zypper se -s`, for example - or if you prefer the long form, `zypper search --detailed`. How do you get that information from any of the apt tools, or even aptitude?
And then there's the openSUSE build system.
But I digress. I will attempt to replace my openSUSE installation with NixOS and if I miss my automatic KF5 builds, I'll try to create Nix packages for them.