I bought for my daughter for college a MacBook Pro A1260 it is running with the 2.5ghz c2duo,2gb ram and a 250gb hd on snow leopard. She had a brand new retina MacBook but it was stolen,she never hardly used it anyway,she mainly uses her iPad Air 2,but she needs a laptop for occasionally the things an iPad can't do. I wanted to get another newer model,but with the holidays and I just got an iPad pro,it was all I could afford. It says that it should be able to run El Capitan according to compatibility list but I don't want to bog it down. My question is which OSX should I upgrade to to still have it running fast and smoothly? I.e. ...Lion,Mavericks,Yosemite or El Capitan ?