System Settings:
In KDE 4.x system settings is divided into a "General" tab and an "Advanced" tab, but why is that? As far as I see it everything in System Settings is advanced and should be treated as such. All icons/settings should have been gathered into one view and grouped. Opensuse does a good job, I belive mandriva and PcLinuxOS does the same.

KpackageKit:
I like its functionality, but it is a bit too awkward to use. There is one view for searching for a program, one view for updating and one view for settings. Why in the world force the user to that many unnecessary clicks? Synaptic does this much better and so did Adept, which was replaced by KpackageKit. I don't understand why the developers cannot see that it is important to reduce the number of mouse-clicks. Adept GUI was much better than KpackageKit! If it was perfect I don't know, but gave you everything in one view which is better.
What happened to Adept by the way? Why is KpackageKit considered to be better?

System Settings - There was a request a while ago to reorganize the items, but it looks like it didn't get very far. There are a number of people who agree that it really should be reorganized.

KPackageKit - I agree. KPackageKit is a mess and rather cumbersome to work with. I seem to remember liking most of Adept, the few times that I'd used it, though I ended up just using Synaptic because it was cleaner and seemed easier to find/do what I wanted.

System Settings - Now in KDE 4.5 it has been organized in much better way.