I have more than 1 TB of data so no matter what option I go with, I will need external storage. I also have some Windows laptops. Would be nice to have access to photos at the very least and maybe music. Here is what I understand USB - cheaper, but directly attached so files can be shared and viewed, but not necessary directly edited by Windows laptops. I typically leave the computer on 24x7 so access should not be a problem from the other machines NAS - more expensive. Slower performance? But files can easily be read and written to by all computers. Also would look at a time machine backup for the internal system drive. Where can this be written to? I don't want to have to buy more devices than I need (for example would rather buy a 4 TB external drive than 2 2TB external drives if necessary). Backing up the data to time machine is not as important to me because I already back it up to the cloud via Crashplan. Still, if I have the space can I backup everything to the same external drive? Should I create 2 partitions? Thanks for the help.