[noggin]

From what i ve read Libreelec does not support 4K HDR content yet.. (on intel nucs)

I thought HDR will be supported on latest NUCs? Maybe ask on the LibreElec forum.

Kodi on a NUC (to me) is a way better user experience than on an AppleTV with MrMC. I did not notice any difference in video quality.

I’d way prefer LibreElec over Kodi on Windows but my NUC8 misses out on Intel drivers for HDR so I’ve switched. I did try CoreElec on an Odroid N2 but the NUC is more snappy. So I’m now ‘suffering’ Windows...

There are two or three issues - hardware support, driver support and software support.

At the moment there is experimental HDR support in Libreelec for some Intel-based devices (including NUCs) though it does depend how the HDMI output is implemented (Direct HDMI to the SoC, or DisplayPort output from the SoC converted on the motherboard to HDMI using an LSPCon chip).  However AIUI the output is limited to 2160p30 and below, and there is only support for 8-bit HDR output (though dithering can reduce the impact of this), rather than the 10-bit ideally required.  There is no Intel driver support for 4:2:2 12-bit (which is how most consumer devices carry 4:2:2 10-bit HDR), and 4:4:4/RGB output is limited to 8-bit AIUI.

Things may have changed - and 4:4:4/RGB 10-bit (and 4:2:0 10-bit for >2160p30 output) may have been added - but I stay across the threads in the LibreElec forum discussing this, and still no massive joy in this regard AIUI.  Intel don't really seem to have a strong handle on this area in Linux, with Windows support potentially being a bit better (though HDR in Windows on Intel is limited to Core-i series CPUs and above).  On the others side - it's possible to get HDR output from GeminiLake Celeron and Pentium SoCs in Linux, and that's not supported in Windows at all...

Intel + HDR + Linux are still not in a fully 'business as usual' state.