With 4 drives in, a 2TB, 1TB, 1.5TB, 250gig (just had it laying around) it's pretty fast and quiet and cool. With the used ones getting cheap, price is no longer a big barrier for easy redundancy. I use it for Time Machine backups and things like installers that I want to archive that would be a pain to re-download etc. Those are of course not true backups as it is a single copy, but it's reasonably secure. That said: copying things to this is NOT a backup strategy, since there could still be cases like file system corruption, viruses, etc. But it is WAY more robust than a single drive, and it also scales up to large capacities that are not available in a single drive.
Verified purchase: Yes