So Far So Good
The 320 -> 640 clone appeared to go smoothly. My Macbook is running with the 640GB HD installed, and everything is looking good. I’m currently copying my user folder from the iMac over to this machine, it’s about 250GB of data so it’s probably going to go all night and some time into the morning I’d imagine. Just as a test, I opened up Aperture and all my photos were there, no issues that I could tell, so that’s certainly a plus as well. Keep your fingers crossed, hopefully the tech gods will continue to smile upon my efforts.