I love it but I definitely wouldn't call it rock solid. I have occasional small bugs here and there and especially with the Plasma 6 switch I've had the whole desktop going down (and taking all programs with it). That has been fixed though.
I was not satisfied with Plasma because I would have different window styles etc.
With Plasma 6 I removed all themes and all the shit and customized it with builtin features only. It looks so nice and clean and just works like a charm.
Encountering sleep/black screen bug is not freedom. The average linux user is shifting, its not longer being used only by teens/tech savvy. People want to get things done.