I've owned the 2012 Macbook Air and recently sold it to purchase a new one. I've been agonizing over the same issues you have(refurb rMBP or MBA) and decided to go with the rMBP. I realize it's the near the end of the rMBP product cycle, but buying one of these machines for about $1300 after tax is the best deal you'll get on a retina screen for awhile.
I am a student and would have loved the extra battery life in the new Haswell airs, but at the same time I spend 8 hours a day(most days) looking at the screen on my computer and I want to look at something stunningly beautiful. I've had the laptop now for about a week and have had zero problems with it. It's a bit smaller than air, but has a more substantial feel when you pick it up. The i5 handles everything I can throw at it(20 tabs in chrome, iWorks, photoshop, itunes, 1080P videos, and light gaming like Civ 5) and I'm excited to get more improvements when Mavericks comes out this fall(GPU accelerated UI graphics).
You can go with the Air, but now everytime I look at my girlfriend's MBA I see a huge silver bezel around a subpar screen(thanks for that retina screen). I love being able to bump my screen real estate up to the highest setting and have 2 or 3 different windows fully display(great for writing research papers cause I don't have to keep switching spaces like I did on the MBA). Overall I would give this laptop a 9/10 value proposition at a $1300 price tag.