OK, so it sounds (and from googling about as well) that this drive should be practically silent. I'm SuperDuper!ing back to my original drive and the Scorpio is going back. Logsi, it'll be interesting to see if the replacement is quieter but mine certainly appears to be a lot louder than I expected. If the replacement isn't as loud then I'd suggest you return yours as well.
Yeah, i would be very intrigued to see hear your findings.
Mine vibrates my desk and physical vibrates the MacBook case a little bit. My HDD is the one that apple ships with the 320GB 7200RPM upgrade so i think it may be the seagate?!
EDIT - Yeah, it's a seagate. ST9320421ASG Very quick drive but vibrates a bit!