I currently use an Apple TV 4K, which is - as far as I'm aware - more or less the best streaming box you can buy. However, it's the version without ethernet, and Steam Link has become a dog over wifi for some reason. So I figured I'd look around to see if there's an alternative solution.

Hardware-wise, I have a Dell Optiplex 3020 or a 2014 Mac mini (running Debian), to choose from, but have no real idea where to go from there, beyond the vague notion that KDE have put big screen mode back into beta. I did have a play with that a few months ago in a VM, but was struck that there were (obviously) no applications that made any real use of it.

Does anyone out there run anything they've built themselves? If so, what?