I own both, 80% of the time I only use the Air, the MBP comes in handy because the HD is much larger then my Air. But I also have an external drive connected to my airport now and I use it to hold stuff I do not need much. The Air is great to use and makes me hate going back to any other laptop. It is so light, easy to travel with. But I must admit, I do not use laptops as much as I used to with the iPad 2.