I already have a shield, and it is 100% the best device I have ever owned. I got it mostly for Plex, and the options to pause/record OTA TV.
My bedroom TV is a dumb TV, and it currently uses FireTV, but 90% of the time I watch Youtube before i go to sleep, I have a chromecast, but that is not sadisfying... I just want something with a remote.
What are some of the other AndroidTV options out there?
Are you wanting a new device just because Youtube is going away on FireTV? If so, I would wait until it goes away and see if there's a workaround. I assume simply sideloading Youtube will work.