ODROID C2 vs Mi Box

HI All.
I am torn up between the ODROID C2 and the MI box. Not sure which one to buy.
C2 costs approx $89.99 (AUD) + $57.00 (AUD) EMMC FLASH 16GB = ~ $150 AUD (thats without Wifi ?)
Mi box costs $119 .Period.

I have a 4K HDR TV that i would like to use it on.
I am not hugely fussed on HDR , I dont have any content and i think it will be a while before content in more easily available.

I am after a player that can stream 4K from My NAS. Must be fast and smooth (GUI).
Should I look at AC wireless to aid the 4K streaming ?
Anything else i need to consider for Dolby Atmos 7.1 sound support via and Yamaha receiver ?
Can I load Librelec on Mibox , In case i want an xbmc only flavor ?