Sorry, but I have no experience with Synology. After some rocky experiences with Drobo in the past, I was looking at alternatives. But, I always came back to Drobo for whatever reason.

The Drobo S I'm using now has been rock-solid and is fast enough for its use as massive data storage. Since it's locally attached (not a NAS), it can be backed up with Backblaze which was a requirement for me.