Summary: I've been using this Seagate backup drive for a couple of months and so far it has been working flawlessly. It's ready to use with a Mac right out of the box, but I reformatted mine because I wanted to divide it into two partitions. Doing so was fast and easy with Mac OS X's Disk Utility app.
Summary: Died on me after 2 years of use. Luckily these have a 3 year warranty and I was able to get it replaced for $10 from Seagate. They sent me a USB 3.0 4tb drive so it was a nice trade up for 10 bucks!
Summary: Worked fine as a backup drive until I plugged it in one day and it did not work. It had been less than 48 hours since I had plugged it in prior and it was not dropped or moved. But lo and behold, it just stopped working.
Summary: Seagate used to be considered among the most reliable hard drives but I probably won't buy any in the future. This unit failed within 16 months of purchase and almost cost me the loss of 10,000+ photographs (I'm a professional photographer).