I have a 6.2 MBP. 2010 model. I have upgraded Snow Lion and Lion. Everything works well. So I was just wondering if I should do a clean install of ML this time? I have an external disk that I can use to save my home folder. I also use a online backup service. Not sure how to go about doing a clean install from a down load from Apple. Perhaps I can find a how to some where. What do you think?