I can save $400.00 by buying an early 2011 MBP 17" vs. a late 2011 model. What does the late 2011 have to make it worth $400.00 to me? Or would it be better to buy the early 2011 and use the savings to upgrade the ram from 4GB to 8 or 16GB? Also the early 2011 has SL vs. Lion. I do have Lion server on my late 2009 Mac Mini. 