I went with RokuTV. They have the best long term support track record for old hardware. 4K Roku hardware is powerful enough. You don't get wedded to a platform that will be abandoned in four years.

I have a Samsung smart TV for work tasks that has the most annoying behaviors built into it. It always insists on "identifying" an HDMI source which it can't do because I've never put it onto my network. Roku doesn't appear to do this kind of data exfiltration.