Some first reaction feedback:

It's good but there are two things taht I don't like.

1.) It uses Breeze system tray icons that I am not a fan of at all; they look very outdated, not fun, boring, and its a smidge hard to get information out of them.

2.) Again in Dolphin, it uses the Breeze icons in the Places tab. I really don't like those minimal icons; there's no fun pop color, while at the same time looking modern (ala Kora).

Just to give you an idea of what I mean by non-perfect icons.

I think the overall culprit in Plasma, and as evidenced here, is that I feel Breeze is a really bad icon theme. And a lot of people use that as a starting point...which leads to unsatisfactory results.