Based on Ubuntu, is KDE's "flagship" OS (so I trust they know what they're doing with their own DE), and is the first to get bleeding edge KDE updates. Everything else is pretty much standard Ubuntu.
I installed this on my wife's aging laptop to breathe some new life into it. She's not tech savvy but gets along with it just fine. Mission accomplished.
Funny side note though, because Linux doesn't force you to update unlike Windows, it means she just doesn't ever update the thing. I've opened it up a couple different times to see pending security updates ready to download. 😆