For my late 2012 Mini, with the basic 1TB drive, I have a WD My Passport attached to a USB3 with incremental backups daily via Time Machine. I have a lot of ripped DVD's and music on my HD that I absolutely do not want to do over again. So I just ordered a 1 TB Seagate MyBackup Plus for Mac that I will use with my T-Bolt Go Flex adapter and using SuperDuper, I will make a copy of my hard drive about once every 2 weeks. Overkill? Of course, but it makes me feel good.