I will list what I have and what I want to do, then my questions: Late 2006 iMac (5,1) running Snow Leopard, 10.6.8 (mine) Early 2009 iMac (9,1) running Snow Leopard, 10.6.8 (husband's) -- ram upgraded to 6 gb. Want to do two things: - Migrate my data from 2006 iMac to new user account on husband's 2009 iMac. Will use Migration Assistant via ethernet cable. - Upgrade OS of 2009 iMac. Snow Leopard is comfortable but alas, obsolete. Please note, this will then be mostly my computer, since husband lives on his iPad. I prefer computers to tablets. Late 2006 iMac will be retired, with hugs and appreciation for years of good service; just getting too hard to do anything on it. So here are the QUESTIONS: 1. What order should I do this in? First migrate data, then upgrade OS, or vice versa? 2. Should I go all the way to Mavericks, or buy an intermediate OS for $20, Lion or Mountain Lion? (All will be new and unfamiliar to me, for the moment.) Your guidance will be greatly appreciated.