I would stick with KDE neon unless there is something that you cant live without in Fedora. The KDE developers and enthusiasts seem to be rallying around KDE neon so it's only going to get better and it has a hybrid rolling release model which is nice.

I upgraded from Fedora 25 to 26 alpha a few months ago and even then the process was smooth and the resulting system stable.

Haven't tried the KDE spin but I did try KDE neon briefly earlier this year. Quite slick but I quickly ran into broken package dependencies when trying to install some random stuff I needed (QGIS and sqlitebrowser IIRC); apparently it's been an open bug since September last year [0]. Didn't leave me with a good first impression but I'm rooting for the project - KDE is fantastic these days.

[0] https://bugs.kde.org/show_bug.cgi?id=368792

I'm using a lab that is built on top of a KDE spin. I really disliked GNOME, and I was a LXDE user for many years.

For me, KDE has been working great. It has sane hot-keys, fully customizable, fast, and good looking.

I've had no issues with upgrades on Fedora yet.

In my many adventures testing out all the Plasma based distro's, OpenSUSE was the most stable and polished version of Plasma available right now.

I've used the KDE spin since GNOME 3 came out, and I love it. I wouldn't dream of going back.

I guess this means it now gets enough attention? Last I tried (n years ago) it felt like a second class citizen.

KDE Neon is wonderful IMO.[0] I like the Ubuntu base but I never liked Kubuntu and I really didn't like Unity so I never used it much after they left Gnome 2.

[0]: but then again I always liked KDE except the 4.x series which was too experimental IMO.