When upgrading to Mavericks, will the Safari, Chrome and Firefox bookmarks be saved or will it require a reinstallation of the browsers? How about photos? I'm thinking that I'd like to do an upgrade as opposed to a reinstall of OS-X. If installing Mavericks for the first time (vs. an upgrade only), I presume that all browsers, photos, data, etc. would be lost and a backup should be done first? Thanks for the help.