i heard alot of people saying upgrading is bad because its not "fresh" but doesn't it just write over the tiger files? what is so bad about that? and ive been wondering how does a archive and install work? do i need a external drive? will it take more GB than upgrading, what does it do with my documents, music, videos, pictures, settings, bookmarks, printer settings, and other things? and does upgrading make the system slower?