I try to help here
My advise-is the same as always.
If you only watch HK drama and movies.
It is better to download and watch
real hd rather than a media box.(video source a real factors and broadband speed and stability-4mbps maybe a problem).

For long term-
1-build a low power/cheap pc
  (Using a 6 years old-Intel BOXD510MO CPU combo-no longer available, but to gave you some idea)
  (do not need a big drive in C-60g.And external drive-1 or 2 TB)
2-Get a good seedbox provider-200gb-RM25.00-30 p/month(depend on RM exchange rate)
3-Get a VPN Provider-RM11.00.(depend on RM exchange rate)
4-get a mid level UHDTV-since you are getting one.(6000 series is good enough)
with these you can watch your movies without interruption and in real HD.
this is my personal view-after so many years with media box.

Using USB 3.0 Hub with 64USB Flash Drive and 120mm fan.
I think mibox do not have the power to support the fan.
Occasionally shutdown and wi-fi disconnect (daily stream 12 hours live tv)
So used 5V dc supply to parallel support the fan and usb hub.

picture is worth a thousand words

[attachmentid=8623349]

depend if you want to watch it in hd or sd video.
if into hd and without interruption, forget about media box.
I suggest getting-
-seedbox
-invites to private torrent-i.e hdchina,hd-torrents,azdrama-chinese drama(just to name a few)
-vpn(if required)

Suggest to use media only for live stream news or documentaries.

The model is MDZ-16-AB. It comes with June 2016 firmware and the updated firmware is dated October 2016.
It is the same like Mi box chinese 3S which are sold cheaper. The difference is the International version comes with Android TV and google cast while the 3S is using their own launcher and miracast.

Is it worth it using Android TV and Google Cast?

For me, yes.

My family watches YouTube a lot. My son uses the built in YouTube app while wife and I google cast from our phones.

Besides that we also Netflix and iFlix a ton. Plus Kodi plays all my local media files.

We don't watch 'free streaming' iptv or sports streams, however.

Where u get the Live TV?

I'm very interested with this seedbox thingy. Just learn about it today. So, how much in average the cost to run this setup? what do I need to get started? Is there any dedicated thread in LYN for this?

you can use "Castaway"from the natko1412 repo

Is it worth it using Android TV and Google Cast?

actually you do not need a android tv(smart tv).to save cost.
if you get a mi box3 international version with(chromecast ultra built-in) you can cast 1080p video
from android phones(heard also support iphone-I haven't try it on my iphone yet.
and voice command -Google Home-to cast video to your tv.

Why need to cast from phone if can stream directly from the box? The phone u can use for something else

there are time when you record videos on your smart phone and want to view it on bigger screen.
I want sure you want to view on bigger screen and not the 5-6 inches screen right.And smart phone today
can record in 1080p.so why not?no wire.just on w-ifi.

Google photos can cast to Mibox or Chromecast from iOS and Android phone.

Google Cast technology is not the traditional mirroring of what's on your phone to Mibox. The Mibox is taking instructions from your phone but pulling media from the internet. Hence I can open YouTube app on my phone, cast a video or playlist then even turn off the phone or leave home. Mibox will continue streaming/playing the content.

This for me is better than what Miracast offers.

As I notice, mi box 3s international or Malaysia controller is using Bluetooth while mi box 3s china using infrared, which one better?

Can I airplay or mirroring my iPad Pro iOS 10 to tv using mi box 3s Malaysia/international? China version?

End of March almost ending.
Xiaomi promised Android 7.0 update coming early first quarter 2017.
Hope Xiaomi keep its promised, not to go the same route as the Mi Pad.