The main difference for the download option is that you are responsible for keeping and maintaining your own copy of the installer and install key. If you burn those files to a CD after download, then you should be set.
I am just picking up on this because AppleCare wiped my hard disk clean. :-( How can I re-download the program disk images? I had paid for "2 for the price of 1" because I needed both a MacOS and a Windows version. Now both are gone! (The download links, though still visible, have expired!)
Thanks for any suggestions!