I have single digit TB in it, and my synology HyperBackups fail extremely infrequently. (I'm not willing to attribute the failures to their S3 implementation, since our ISP kind of sucks.)

Anyway, I haven't seen any apparent data loss over the last few years. I'm considering doing a full restore, just for the heck of it. (Especially since this article convinced me I should start replacing the aging drives in my NAS!)