I decided to go ahead and update to a new 500 GB Hard Drive for my 13" MBP (mid-2009). I bought a WD Scorpio Blue with 5400rpm. It turns out that it does do the frequent parking when the computer is idle and is extremely annoying. I don't want to do HDAPM in fear of battery life loss. I'm going to return this drive and buy a new one. But which drive is going to not have this problem, be as fast, cool, quiet, and have low power consumption. I'm still going to get the same specs as that WD one I have now that also doesn't have any drop protection. Any Suggestions? And by the way, the stock drive that came with my mbp was a Hitachi 160GB 5400rpm.