[noggin]

So @wrxtasy Which mediaplayer would you buy for 4k HDR playback (excluding DV)?

I already own the Eminent EM7680 which has a AMLogic S905X-H SoC (based on 4 Cortex-A53 cores, and a Mali 450 MP3 GPU) running on CoreElec. It should be able to support 4k 60 Hz, BD-ISO, DVD-ISO, h.265, HEVC, VP9, HDR, HDR-10, Dolby True HD, Dolby Atmos, DTS-HD and DTS-HD MA.

and I have a Minix Neo U9-H which has an 8 core AMLogic based on the same Cortex-A53 and a Mali 820 MP3 GPU. It is running Android right now, as I want to be able to use Netflix and some other tv apps.

Do they suffice for 4k HDR with the correct Max CLL/FALL?

No see - https://forum.kodi.tv/showthread.php?pid...pid2823690

Not until we are using a Linux 5.3+ Kernel and a stable Kodi v10 Matrix release, late next year I suspect.

If using a OLED, the closer your display's brightness is to a Sony BVM-X300 OLED mastering monitor, that hits 1000nits - the more accurate your HDR10 Movies & TV series - picture output will be to the creators intent.

Panasonic and LG are producing pretty decent OLED's these days.
I'm sure you have seen THIS Shootout (click)

There is a bunch of great info about that BVM-X300 and the visible advantages of HDR in general in THIS article. 

Worth pointing out that the X300 isn't the universal choice for mastering these days (and Dolby Vision content has often used a Dolby mastering display).  If too much of the screen is in the HDR range for too long, the X300's display goes into a protection mode to avoid overheating, dimming itself, and ceases to be calibrated. There is an amber warning light on the front that flashes to tell you this is happening - basically that lamp means 'don't use this image as a reference any more'. (I think this is also used to avoid OLED screen burn when displaying static content for too long)

There are now other reference monitors that avoid this and are well regarded. (Eizo do a well respected LCD model which has a backlight per pixel effectively AIUI)