What I can tell you all is that I’ve had the 65" version of this set for a few months now and it is AWESOME in every way.
They’ve recently updated the tv’s firmware and you can now select apps directly from the screen such as Hulu, Netflix, etc. However, the 6" tablet works absolutely perfectly and is a full Android tablet and not neutered. So, you can add any apps to this tablet that you would add to any other Android tablet. Obviously you can cast from the tablet to the TV. The stream is sent via your network connection. The faster the better.
Your best bet, as always, is to hook an Ethernet cable to the set for the best bandwidth. Especially when you’re streaming full 4K from Netflix, Amazon, Vudu, etc. Wireless still doesn’t hack it for this. It can be done but not as well.
The 65" was $999.99 and was a steal at that price. I’m not sure the increase for 10" more is worth it but that’s up to you.
Also, I’ve hooked up a Logitech Harmony Ultimate to control my system and it controls the TV just fine. So, if you’d rather use a buttoned remote than the tablet, you can. Also, the remote supplied with the TV is an older version but there’s an option to get the newer remote (required for on-screen navigation) for free or $5.00.
The display is just great. Blacks are black, colors vivid, resolution is amazing. You can’t go wrong with this set.
Note: When I first set it up it required several updates to the software on the TV itself and the tablet. So, be prepared to do multiple updates. Also, pairing the tablet to the TV could be a little tricky during this initial setup but once completed it’s great.
If you do get this set, enjoy! I know I am.