For what its worth, I think building a NAS has a few benefits, one being Native Level ZFS support if you use FreeNAS. Synology has gone in a different direction with btrfs and LVM, and I wish they would just stick with ZFS in User Space instead. Synology has managed to do a lot in their consumer lineup, they've even ditched ARM for x86 so they can offer Docker/LXC which is a big win, even if its not as performant as my own Proxmox stack off consumer hardware. That said, use what you feel comfortable with.