I just ordered a 540040 with the intention of either replacing the stock 40GB drive or adding a second 300GB drive. Looking at Weaknees, I see if you want to add a drive, they want you to send the unit in for them to do the work, but if you want to replace the drive they sell DIY kits for that...and that they sell the brackets and other accessories necessary for adding a drive yourself. I don't see anything in their FAQ about why they have this policy. Is there some complexity (other than the need to expand the swapfile) in taking a 40GB unit and adding a 300GB drive? Am I better off just doing a drive replacement and putting the original 40GB drive on the shelf as a "backup"?