I am looking to purchase an external, 1TB HDD to backup my 250GB Blackbook: 250GB Clone, with the rest split between archives, TM, and NTI Shadow; although I have considered archiving only to DVD. I am planning to enclose the drive in a NewerTech MiniStack v.2.5. I have narrowed down my choices to: WD Caviar Black Hitachi 7K1000.B Hitachi E7K1000 (but waiting for a review apart from initial speed comparison against the original 7K1000) WD Caviar Green 10EADS (not the older 10EACS) My concern with the WD is the vibration but it outperforms the Hit 7k1000.B in I/O and access time. The 7K1000.B is a good all-round performer with modest power requirements, so it will hopefully keep cooler longer. The WD is an option but it is the low end performer. So, my question: When deciding on a hard drive that functions solely as a backup drive, what is the most important spec(s)? access time? I/O? throughput? sequential read/write speeds? random read/write speeds? Each drive has strengths and weaknesses and knowing which spec(s) is most important would go a long way in helping me decide. Also IIRC, the Hitachi and WD Black drives all have 5 year warranties, while the Caviar Green only has a 3 year warranty.