I've been using Slackware64 -current for a few days now as my main production machine. Its fast and stable and has given me no known problems as of yet. I have a couple of annoyances though, which just may be my own fault.
I can't find File Manager Superuser - is it gone?
The next thing is that in System Settings, there is no box to start Administrator Mode. I could always start a KDE session as root, but I don't want to do that.
I usually change the default run level to four, and set up my self to login automatically. I do this so that my wife does not have to login and startx to use the computer. It usually runs all the time, but sometimes a power failure or storm comes along that requires a re-boot or shutdown. My wife just wants it to start and run.
The K kicker has no Run option, but Alt + F2 works.
I realize the Slackware Team has nothing to do with KDE itself - I'm just wondering if I'm looking in the wrong places.