I tend to stick to caviar blacks for a single HDD, and only use cheaper drives for my raid enclosure, but that's more a matter of personal preference. The spinpoint isn't dramatically less reliable than the cav. blacks by statistics. That HDD just stuck out as the rest of your build uses high quality enthusiast-standby parts.
If you think you'd like to add a 2nd 670 down the road, your PSU is fine.
the coolermaster is a great standby as well as value for your dollar. It will hold up nicely under moderate overclocking. If you want to push the 3570's boundaries, however, you might want something a bit beefier.
other than that, your build is solid
p.s. check out steelseries mice, if you haven't already. They make extremely high quality, no frills mice. I'm admittedly biased against razer since wasting money on the boomslang - their first gaming mouse, over a decade ago.
Been looking for a good deal on a 256gb 830 or any 240gb toggle NAND sf-2281+ so i can stick the 120 i have into my laptop. Dunno why it never occurred to me to check amazon. I blame lack of coffee >.<