I use KDE bigscreen on my raspberry pi 5 media center, and it is a very cool idea, but does not work the greatest. I love that it is a desktop environment that I could theoretically navigate with purely a remote. I do not love that my icons keep spam refreshing for some reason. I do not love that every time a popup window comes up it treats that popup window like it is a primary application and hides the UI. Meaning every single time i connect or disconnect a bluetooth device, popup window comes up, and i must manually close each one in order to see the UI. This is not a huge hassle, but its a small annoyance and one that I do not know of the fix for. the fix might be switching to a bluetooth system that does not have popup windows.
I have never gotten far into normal desktop KDE plasma, so I cannot comment on it. The main thing people love about it is how customizable it is, but I have never had a problem with gnome’s customizability, so I dont see how it could possibly be more customizable than gnome.