Ok thanks Starges. Yeah, for the same price, I need to compare performance vs $/mb. Speed is obviously important, but I want to the drive to be reliable, quiet and run cool with low energy consumption. I should have made a poll!
For a HTCP and non-primary drive, how much speed do you really need? If it is for video, it is sequential reads. I bet the drive can output faster than you can watch a video. I'd go for the drive that saves the most energy, quiet, lowest temp, least expensive.