Hi All, I am considering selling off an old laptop and swapping it for a used MBP. I recently bought my wife a rMBP 13" and she is loving it, so theres no option of prying it away from her. This isn't so much of which one to buy, but which one to AVOID, and when I set my eyes on one, what are the due diligence to make sure I get a decent machine. I had my eyes set on a cMBP from 2010 or 2011, so I can upgrade the ram and SSD. Are there any models I should avoid? (e.g. the one with the 8400, which has a really high failure rate) I will be buying locally, so when I get the machine, other than looking at the screen, and running an apple hardware test, is there anything else I can do to cover my bases? Is an AHT even worth it, how long does it take to run, will I be waiting in a coffee shop for 3 hours?