Personally I would go for ubuntu xenial as it supports both aufs & overlayfs.
libreelec at a glance looks like a cut down ubuntu maybe debian.
Also the kernel 4.9 as the odroid guys with the usb/sata bridge have chosen that for a reason and I am presuming its part of the usb UASP sata FIS stuff and with all the vendors doing there own special USB extra’s rather than a singular strict RFC its taken to 4.9 to get to a stage where the device trees are getting somewhere near capable.
I am still waiting for a Rock64 and wanted to hear more about that usb-sata bridge on the oDroid.
Thought I might have the Rock64 by now but maybe I should grab an oDroid HC1.
In fact an Xu4 so I can chose which sata bridge or not
oDroid is mainly on Ubuntu 16.04 4.9 with Rock64 on Ubuntu & Stretch 4.4
I would say go with Ubuntu and backport 4.9