disclaimer: KDE contributor.
But it also reminded me why I have never liked KDE - it just feels too busy with too much going on. I prefer things simpler visually as well as functionally. Yes, I'm one of those people who are quite happy when Gnome go around removing configurability (right up till the point it is an option I use). I try to use defaults as much as possible and find it important that they are appealing and well thought out.
But if you are a person who prefers to stick with defaults, well, KDE's defaults are very old and plain.
The useful bits of Gnome shell show up when you press the Windows key (far easier than trying to find a spot on a dual screen setup). Sure you get the window selector, but far more usefully you can start typing stuff and it finds useful matches (apps, contacts etc). It also has a nicer notification system, as well as improved 'tray' (whatever they call it).
I did have both working in an earlier release, but the panel was from a third party and they break on every gnome release.