A bit of apples and oranges: iDrive has tiered pricing limiting you to either 2Tb or 5Tb storage, while Backblaze offers unlimited storage. iDrive offers business plans, but Backblaze offers plans linked to backing up a single device. If you’ve got terabytes of media hanging off a Mac (or a wired NAS) Backblaze is a far and away better deal. iDrive isn’t bad, but it’s aimed at a different customer.