Yup.. Though I haven't even jumped on the 4K TVs bandwagon yet.. Not to talk of HDR features.. Giving the industry a couple more years to mature, before diving in. Tech can only get better and cheaper.. 

I saw that only certain certified android box support Netflix 1080p. Is that true?

True.. Noticed it doesn't have an Ethernet port.. .. Don't tell me Xiaomi is now taking specs design advice from Apple...The cost of adding an Ethernet port is negligible.. A USB hub with an Ethernet port would not only cost more, for those who'd insist on an Ethernet connection with the MiBox....but since it only has a single USB 2.0 port, both Ethernet and disk I/O will be struggling for a finite amount of time and bandwidth... Oh well, a good 5Ghz router + proper placement should ease that a bit.. On the plus side (depending on who you ask), it's running the Android TV 6.0 OS and can output Netflix at 1080p.. The review video I watched saw it struggling to achieve 4K res on Netflix.. Probably due to poor connectivity or a software bug (reviewer was using a USB hub with Ethernet). Hopefully can be fixed in a future firmware update.. The Nvidia Shield remains the top dog..

Mibox has remove Eternet Port long time ago. my previous Mibox 3 did not come with an ethernet port.

It's no wonder then why many have faced issues while streaming content..
The Nvidia Shield box, a device released last year is capable of playing actual 4K H265 files and output at 60fps.. Most, even the latest Xiaomi box can only output at 30fps max.. No surprises there..
True.. It's not my cup of tea.. Still sticking to the decision to wait for the 2nd generation Nvidia Shield TV...Should Nvidia release one 

Is it safe to buy minix neo u1 from taobao? Which minix neo u1 model should i get?

Internet connection?

Picture "quality" is determined by the file, box settings tv settings, and avr if u r using one via hdmi.

For same file, it will be about the box and tv settings.

I assume u r using a 4k hdr tv.

Q10pro... besides the parameter control, try the android settings, advanced settings, play with the sampling type. I find 4:2:0 10 bit to give the deepest colors for playback.

Also, check from time to time the video setting... when u go to kodi or other apps, it will adjust to 1080i 60hz or 1080p 50hz. For playback, set it to 2160p 60hz.... this, i find is best... for any file playback with native player.