Asking as I've got a lot of spare components lying around that I'm planning on turning into a NAS. If it doesn't work out I'll buy a pre-built enclosure and reuse the drives.
Got a Xeon E5-2690v2 with TrueNAS Scale and a Synology DS418. Having used both pretty heavily over the years I can safely say I'm indifferent. The Synology is efficient; the TrueNAS Scale box performs really well with the added bonus of being able to run Kubernetes and Docker workloads. They're both sitting in their respective corners, doing their respective things, with minimal intervention.