This is a massive improvement over the 1st Gen cube! Voice control is responsive and accurate, setup was pretty straight forward, and it works really well with my TV and AV equipment. Netflix and Prime Video work well with both voice and remote control, I didn't have any trouble with 4k HDR or Dolby Vision stuff. I was able to play some Dolby Atmos (DD+ streaming version) content over Prime Video. Overall, this is an excellent box for a person who streams everything from online services! The upgrades are welcome, anyone who was frustrated with the performance of the first gen Cube but intrigued by the functionality should probably give this one a chance!
If you use Plex, Kodi or similar... the experience is less than desirable! The box doesn't do passthrough for lossless codecs such as Dolby TrueHD, Dolby Atmos (non-DD+/lossless version) and DTS-MA. Playing 4k content with any of that causes all sorts of issues while streaming.. including not playing at all, blank screens, or sever stuttering. It's completely unacceptable that a streaming box capable of 4k, HDR/DV and Atmos isn't able to handle passthrough while the original Shield TV has been able to handle this for years!
Also, the Ethernet to MicroUSB adapter is only 10/100Mbps. This is sufficient for any online streaming and most all local streaming, but it's not unfeasible that a local 4k stream could be close to or slightly over 100Mbps. While the included USB2.0 wouldn't allow for actual gigabit, there are suitable gigabit adapters that should allow ~400Mbps for wired. There are adapters which are compatible, though it results in additional cost. Considering the typical Cube user isn't likely to run in to any issues here, it's not really a miss. Also, considering the above prevents a lot of this sort of content from being playable, the lack of USB3 or Gigabit is moot.
I'd hoped this would be a replacement for my Shield TV (which doesn't support Dolby Vision), I was disappointed. I'm also a bit annoyed, there's simply no logical reason for it not to support passthrough.
Overall, I like the ability to come home and say "Echo, open AT&T TV" and have it open and playing CNN while I'm still getting settled... Or "Echo, play the Good Place on Netflix" and have the same. But I don't like that this still requires me to switch back and forth between different devices depending on what I want to watch. Hopefully Nvidia Shield will get Dolby Vision soon, and maybe Netflix will enable Dolby Atmos on the shield (or directly on my Vizio SmartCast TV.