Last weekend my maxed out 13" mid-2012 MBA had a run in with some water, so I ordered a maxed out 13" 2015 MBA from the Apple refurb store expecting the worst. Well I took the 2012 MBA to the Genius Bar for inspection, and they said there was no damage! It was too late to cancel the order for the 2015 MBA, and now it's here. Is an upgrade from a 2012 MBA to a 2015 MBA worth it?[/QU
If you value battery life (i.e. you need to go 8-12 hours without worrying about, or even thinking about, a re-charge) then it is worth it. The major upgrade in battery life came in 2013 and it was really a major upgrade for me. I regularly go off to meetings with just my MBA- no brick or anything else to lug along in a bag or briefcase. I am sure there are other features (perhaps more storage) bit for me, the increase in battery life was a game changer.