I have multiple offices and was thinking of using two Drobo Pros as a storage location for my backups, with one at each site being synced. It seems like on the surface its a cheap alternative to a SAN. Because it will just be used for storing backups I don't think that performance is as big of an issue.

Related question. How do you sync your backups from your main location to a remote site. I am using Backup Exec and wondered if I should use a feature in the program or use something like Delta Copy.