I am looking into getting a new MBP. I am tempted by Apple's prev gen refurb (2.7GHz, 512GB SSD, 16GB RAM NV650) for about $2150. I want a discrete gfx card and current gen is too expensive for my taste, so I have also considered buying a MBP from the Marketplace, but I now wonder how safe it is. How do I tell if I am dealing with the MR member or a hacktivist? Also, what issues should I be aware of before buying the previous gen refurb from Apple? Are there still screen lag issues, image retention, etc., even in the revised hardware (Feb, 2013)? Other issues?