Last year I bought a 4bay WTR PRO NAS with an N100. It idles at 13W, after some tuning (mostly putting drives to sleep after ~10min of inactivity). I briefly looked into TrueNAS/unraid, but I ended up installing plain Debian, with ZFS, pCloud for remote backups and running everything on plain docker (in my case samba, HASS, jellyfin, kodi, rutorrent and some custom apps of my own). All in all it took me about 8 hours to setup, and 0 issues since. 100% satisfied with my setup.