I did the same! I ran MythTV on a PC connected to my TV for a while, but when I wanted to add a second TV I had a really hard time getting a decent fanless cli

I did the same! I ran MythTV on a PC connected to my TV for a while, but when I wanted to add a second TV I had a really hard time getting a decent fanless client at a reasonable cost (this was mid/late 2000's). I ended up switching to SageTV purely for the hardware client. A year or so after SageTV was acquired, I moved to Plex. The biggest miss was the hardware client. I went through several sub-par iterations of PC-based hardware -- including mini-ITX PCs and Raspberry Pi -- but never got a setup that could run Plex, Youtube and Netflix and work 100% without a keyboard/mouse involved. I also tried some hardware -- Roku, original Chromecast -- but nothing was even remotely good as the SageTV HD300's, even years later. Until I found the Nvidia Shield -- though it's more Google TV doing the real magic, I think. I still have the original 2015 model in my living room, still working perfectly. My newer "media room" TV uses built-in Google TV stuff -- I originally intended to use the Shield but it requires upgrading my just-before-4K-came-out AVR to be able to do 4k, so this setup was simpler. I also have a cheap "Chromcast with Google TV" on an old smaller set in front of my treadmill. Over the past few years, I have all but stopped using Plex, though, as we went to pretty much 100% streaming services, but it is still running. It's really thanks to MythTV, though, that I started down this path 15+ years ago. I've never had a cable/satellite TV subscription in my name, ever. It's interesting now to look back, because all my media sources have entirely changed since I started. I do still have everything needed for OTA in a box somewhere, but I never hooked it up in this house -- maybe it's time to give it a shot again.