I think it is time to upgrade my stock mbp HD. Which is better? Seagate ST9320421AS WD WD3200BEKT Hitachi HTS723232L9A360 Fujitsu MHZ2320BJ-G2 ? I am aware of Seagate 500gb 7200 rpm drive, but it is new to the market and I will see how it will perform. Meanwhile 320 cost is about $70-80. I think 320gb is more than enough as I don't use mbp as primary computer. So comment on speed increases, noise, vibration, quality (failure) and similar stuff. Thanks!