I'm thinking of going Air with my next laptop purchase but am nervous about storage options - I currently use 100GB just for system and software, and another 250GB for data, even before accounting for new files created in the future or the media library that's already on an external drive. Since 512GB internal SSD is prohibitively expensive, I was thinking of going with 128 or 256 and using an external HDD via Thunderbolt for all user files (possibly including mail, music, etc.). A few questions about that: 1) does OS X work gracefully with the entire /Users directory on an external drive? Do most applications handle it well too? 2) how does performance with large files on a thunderbolt external compare to performance with files on an internal drive? 3) what happens if the external accidentally becomes disconnected while you're working? Do you have to leave it connected even when the computer is sleeping, if you have files (or just your mail client) open? 4) Some of the work I do involves frequent writes to large files (developing and testing data migrations for large databases). Is this terrible for the health of the SSD?