Google is launching an official Android TV device in May or this fall.
I have the mi Box s and it's terrible. Since the Android 9 update nothing works and it chrashes every few minutes
You will get FAR better support with Apps, especially UK ones with tvOS and an Apple TV vs using anything Android TV (And that inc. Shield)
Plus if you are using mixtures of UK / Euro sourced 25/50fps video content combined with 24p content from Netflix and Amazon Prime - Apple TV’s - Apps Auto Frame Rate Matching for smooth video playback is definitely superior vs anything Android TV offers:
https://support.apple.com/en-au/HT208288
24p content output at 50Hz is a horrible combo.
I have both devices and a Shield. Apples tvOS, and localised App availability and support is definitely superior, for use outside the USA.
What I’m saying is you should really avoid Android TV anything if living in 25/50fps centric UK / Euro / Australasia. Smooth, seamless video playback is a nightmare if using Android TV in those regions.
Or a amazon fire stick 4k. I also have a mi box and a shield. I would buy another fire stick before a mi box.
If one of your options is the Apple TV 4K, why not consider a shield pro 2019 rather than a mi box? It's the same price as the atv and way way better.
Hi all the the mi box has arrived. Any suggestions for sideload apps? This would be required for Amazon prime. Fyi I have 8.1 android version. Would you recommend upgrading 9.1?
Go with Xiaomi Mi Box 3 or 3S. Android TV is far superior. Only the Assistant is big deal. If you want emulation, gaming and go for extra mile get Shield TV 2019 but it is 4 times more expensive.