Overall Review: 6 TB HDD, I just got it a week ago, so I can't really say anything about the quality, but so far it's running good.

Pros: easy to set up

Cons: expensive, not powerful enough for other use-cases

Overall Review: This NAS is easy to set up, like all Synology products, and the system it runs with does what you expect it to do. I am using it as an SMB drive with automatic Backup to Synology C3, and that works like a charm and was easy to set up. You could also run other services/docker containers, but I'd rather have a separate device with more RAM and better CPU for that.