Apologies, I was replying only specifically to the second point - feel of the desktop as a user. As a user, the default Gnome 3 look(top bar only, search driven application launch) feels much better than the default KDE look to me.
I keep the taskbar on the left side(Unity like) I do not see why taskbar on top is superior and the fact that KDE let's me put things as I need is very important.
let me give an example how options are better for me, my right eye is much worse then my left eye so I have the taskbar and notifications on the left, if it was reverse I would move them to the right.
You prefer Andoid/iOS like interfaces on your desktop ? I did not check all apps in KDE but Konsole and Dolphin let you hide the menus(if you need those pixels) also KDE apps let you hide or customize your toolbar so if you nver use the back/forward buttons you can hide them