I have never appreciated KDE and its applications but it’s a matter of taste, there is little to debate. I’ll give them a second look although the fact that you mention K3b makes me think you and I have totally different needs (I haven’t burned a disk in 8 years). You say email is not dead but then you confirm my thesis that Evolution and Thunderbird are dead in the water (or at least they’re not moving). That leaves us only with Kontact…
You mention the loss of privacy and control and that’s one of the reasons for my rant: I think that for the free software/open source movement to give up on developing tools for personal productivity is a horrible mistake for the long term vision.