I have a MacBook Pro from 2009, and I'm buying the latest MacBook Pro. When I use my Time Machine backup to migrate my accounts, applications, documents, and other settings and files from the old MBP to the new MBP, is there a choice between migrating absolutely everything and doing some kind of "cleaner" install? I'm asking because I wonder if some of my system or application preference settings or application support files are out of date, corrupt in some way, or are fine-tuned for the old hardware. I know that bad preferences or other settings files can explain occasional glitches, so there's some merit to starting in a fresh way. I know that to be absolutely clean I could skip the migration step during setup, reinstall all of my applications (if I can figure out how), and migrate files from a backup manually, but I'm wondering if there's an approach that's less severe and less trouble. Does it make sense to do any tidying of this type when upgrading? Is it worthwhile? Is it possible?