Hi all. I am planning on purchasing a used Unibody MBP 15" 2.53 4gb from a guy on Craigslist. However, looking over these forums, it appears like a lot of people are having issues with these new MBPs. The seller would like to meet at a coffee shop, so I'll have a little time to check out the system and make a decision. Anyone have any suggestions for what I should be looking for when inspecting the machine? A few checks that I can do to make sure that it is not a lemon, as it seems some people have gotten? Any advice for how to best inspect the system and key things to look for would be appreciated.