I'm getting my MacBook Pro Retina on Monday. If it comes with Mountain Lion pre-installed what are the benefits of doing a fresh install? In fact, what is a fresh install? And how do you do it?
If it comes with ML pre-installed, you don't need to do anything.
If ML isn't pre-installed, some have simply updated without a clean install and have had no problems. Others claimed they had problems that were solved by doing a clean install. YMMV