Have a mid-2011 MBA with 2GB of ram that I'm on the fence about. My usage is pretty light - though I do occasional dj gigs that require the Mac run smoothly. But mostly used for email, iPhoto, and basic stuff (so basic that I used an iPad last year as my computer - the Mac was a recent purchase.) Anyway, I'm loving the Mac but the 2GB of memory and the quickly dropping resale value is leading me to sell and upgrade. But to what? 2011 13" refurb looks like a nice deal - 4GB ram and 128 SSD would double both from what I have currently. Plus the extra screen real estate sounds nice. Would that computer last me 3-4 years through OS updates, etc? Or better to bite the bullet and get this year's model? The refurb would only be around 250 additional after selling the 11". What would you upgrade to?