Hi there guys! I have this mid 2010 mpb 15" and I think it's getting slower everyday. Now I decided to switch the RAMS an Im looking forward to leave it with 8gb. So 1st question: Is it true what apple says that 2 slots filled is better than 1? So 2x 4gb or 1x 8gb? 2nd: Do I have to use the slower RAM suggested by apple (PC3-8500 DDR3 1066 MHz type RAM) or I could go on an install this one (PC3-12800 DDR3 1600 MHz type RAM), which is the default for the newer 2012 mpbs?