I'm not a power user, but being able to work with files and folders as root was always an obvious thing - a necessity really, since with Linux (and KDE especially) things don't always work initially and you have to tweak and change different system files, often just following proven procedures from previous installations (I've got a special file with all the steps). And I'm not a terminal whizz, so being able to work in a graphical environment is important for me. This has become substantially harder after Dolphin and Kate root modes were disabled, and we have to do workarounds, like using Krusader in root mode. So if, as a user, I should have a voice here, I'm voting for restoring root privileges. I can't think of many things which are as useful.