On my private machine, I use arch with the newest features.
Work related I am using debian testing on the laptop. The packages are not the newest but I know everything is stable and upades are not in my way. (KDE 6 will arrive there late summer)
KDE neon is a Linux distribution developed by KDE based on Ubuntu long-term support (LTS) releases, bundled with a set of additional software repositories containing the latest versions of the Plasma 6 desktop environment/framework, Qt 6 toolkit and other compatible KDE software.
I would not recommend KDE Neon. Qt applications (like Calibre) sometimes have problems because they're taken from Ubuntu(?) repos but Neon ships their own Qt libs which can cause conflicts.