I had planned since June to get a 13" Air. I had had two 11" (2010 and 2011) Airs and was only bothered by the poor battery life. When I heard 12 hours I was sold. I was waiting for the right time and Apple happened to release the later 2013 MBPr and lowered the price. By the time, I added more memory and went to 256GB SSD, the air was about the same price as the mid model (2.4, 8GB, 256GB) MBPr. SO for me it was about screen vs battery.
I tried to go see a retina at two best buys but couldn't find one. I remembered what a difference the retina made when I got my first retina iPad. Decided I'd order the MBPr. Picked it up today and it is the display is so good, I can't believe I considered the Air. I had them side by side in the Apple Store and it wasn't close in any way except the weight. And that was so close, I didn't notice it much. .5 lbs just isn't something I'll notice around my house.
I remember my 11" Air screens being good but the when I was looking at the 13" Air next to a MBPr, it looked terrible. Bad viewing angles and just no where as rich as the MBPr. I am extremely happy with my choice. No image retention issues and the performance seems great. I have been browsing, running Tweetbot, watching videos and even installed some apps for 3 hours and I still have 76% (7:30 hours) battery left.
It's still the first day so I am sure my perception will come down to earth in the coming days but I am sure that I would be more disappointed in the Air.