Good Stuff Neil, I am glad you got a chance to buy and see how streaming works at home since you and the consortium have been working on the tech for it.
I have just a normal 1080p 720p google Chromecast and Fire Stick for my two tv's. One tv is a 4k and the other is a 1080p. Now on my 4k tv I can get 4kHDR content through the tv's OS LG web os and I don't have HDR on my 1080p tv of course. One thing I would like to say that since I don't have a 3DTV, playing my SBS converted from blu-ray disc I watch Anaylglph red/cyan. And the only way to do that onto my 1080p HDTV is to stream the SBS movie from my laptop through my Google Chromecast (first gen) on a play store 3d movie app. Now while I can stream the movie and still have sync in audio and not really skipping video lag but the video resolution is degraded and pixelated. And at the same time on my laptop screen it looks normal at full resolution.
And another thing I have tried is to stream over remotedesktop from my home server that has stereoscopic player installed and it gives a better picture quality but still iffy since I need to stream my desktop from google chrome browser and can take up CPU resources. Over all its a good starting point and a lot of this is over wifi so it does work not to bad in my mind.
I have a plex server on my Xeon Windows Server 2019 computer and comes in handy but I will mostly use my LAN folders to play the movies directly DLNA does have its drawbacks but its really organized with plex and easy to access. One thing I wanted to mention is about the codecs used to play movies and stream games. Alot of the new stuff uses h265 4k and 1080p, the older streaming sticks don''t support those codecs. Also older laptops don't support the game streaming services that well. I went out and bought a new laptop so I could play Google Stadia smoothly. I am looking at getting a Stadia controller and google tv chromecast sometime too.