I've got an 09 MBP which I believe was fully upgraded when I first got it. It's running 10.5.8. In order to upgrade to the latest OS, I need to buy the Leopard disk (i think it's Leopard) first and then I can download Maverick from the app store. My question to you that know more is... Is it even worth it? I mean my MBP still works great. Aside the new battery I need, I've got no complaints. Use it mostly for surfing and email, nothing else really. The other side of me says this machine is 4-5 yrs old and I've got the "I want a new machine" bug. If I bought another machine, I don't think I would get the MBP again, probably go with the Air this time, the smaller one. Is there a way to see the "health" of my MBP as a whole? Thoughts? Thanks!