Reply to Shopping for new Laptop - Looking for opinions...

I'm downsizing from a MBP 15" which has become way to big to lug around. I have a few different options I'm looking at:

MBP 15" retina 2.3ghz - still big but weighs less, SD slot (a must). Almost a desktop replacement.
MBP 13" retina 2.9ghz - nice size, decent power, SD slot. Price to power ratio is the least attractive.
MBA 13" 2.0 - my favorite choice, SD slot.
MBA 11" 2.0 - very portable, no SD slot. Price to power is the best.

Running Traktor exclusively with an S2, F1, MidiFighter 3D.

What does everyone believe??