I have a 2011 MBP. Last week it had to be taken to the store to have a screen replaced (on my last day of apple care luckily). As it would have meant being without a computer for a week, I decided to buy a MBA and then return it when I got my computer back (I pre warned the shop of my intentions and they gave me the green light). The first thing I notices was how much faster than my MBP it was, I mean really, it was lightening quick in comparison. That coupled with the long battery life and the weight meant I really preferred it a lot. If it wasn't for the wimpy SSD size, graphics chip and low processor speeds I'd make the switch permanently. Unfortunately though, my requirements mean that it isn't suitable and I have to wait for MBP's with non-laughable SSD sizes to be affordable All in all, I was really surprised as just how good they are, and for the light user they are super impressive for the price!