[Q]

If MM continues it's very consumer friendly attitude, it is probably safe to use the downloaded version of SE V:
I recently tried to reinstall SE III on my new computer and realized that I couldn't find my registration key (bought the game in 1999!). After an e-mail to MM with a copy of my introscreen of SE III on my old computer, I got the registration code from him again within 24 hours and could install SE III on my new computer.
For me the shipping cost (to Europe) and the time it takes (several weeks) make the download version interesting.