Reading some of the comments on Amazon for these sorts of drives some people say when they are formatted some of these drives report significantly lower usable size, I guess because some may have errors which the drive maps out, and therefore that is what classes them as refurbished? Anyway, it put me off them. Then again, these are much cheaper than £350, so maybe there is another tier of used drives above these cheaper ones where this is reported size thing not a thing. I'm talking like £90 for an 18tb drive on there.