First post ever, sry for the English as not my first language I have this MBP 15' since mid 2009 (unibody) I would like to upgrade the snow leopard to Lion since the Xcode4 only supported by Lion. But the Lion makes a lot of concerns, A friend of my got a late 2010 iMac 21' (i3 processer and 4GB ram ). She installed the Lion which got the common WIFI issue and slower than snow leopard. If this will happen to me or worth like happened to others (WIFI, Heating,etc) Any solution to this or the update already fix these thread??