Mid 2008 MBP. I'm having trouble getting the information I need from the official website so I thought I'd ask here. Am I able to upgrade without wiping my HDD and restoring from a backup? Other than that, it seems I cant upgrade to 10.8 from 10.5. Do I just have to go with 10.6 instead? I'm not paying for more than one upgrade, so what would be the recommendation?