Nvidia Shield
I have both an Nvidia Shield and and MiBox. IMO, They're both terrific. Nvidia has better specs, and if you also love gaming, is most definitely worth the extra money. But if you dont game, and are trying to save a few bucks, MiBox works great and will not disappoint. For video alone, it really is *almost* if not as good as the shield, especially for the price difference.
I really think those are the only two devices to really choose between though. I also have a Nexus Player, and it is slow and clunky...I do not recommend it at all. The MiBox is MUCH, MUCH better than the Nexus Player.
Sony line up
The channel master stream + is close, but does not yet have either Netflix or Prime. It does have ota dvr features that are pretty nice.
You cannot put the Xiaomi Mi Box in any "Best" category when the fundamentals of the device still do not work properly.
I'm telling about problems with WiFi, 5.1 Netflix audio. Hard drives renaming themselves every reboot and the list goes on and on.
It's simply too buggy a device if you want reliability and surround Netflix Audio No matter what the price.
You could've simply searched. There is only one.
pretty much only the Mi Box and Shield TV are readily available for purchase (NP is discontinued) and the better of the two is the Shield TV by a wide margin
I would recommend going with a separate box rather than a TV with ATV as its OS for better performance and more flexibility with upgrading
Shield TV, no competition.