I am having the same struggle. A fully-loaded MBA will be pretty much the same price as the refurbished rMBP. Which one will last me longer?
I went to the apple store today again and checked both machines out. The "extra" weight on rMBP is barely noticeable. At the end of the day, I go to school in New York and my campus isn't that big after all. Carrying a laptop won't be a problem for me.
The similar price point aside, the battery life won't really be a concern of mine. As I always carry the charger with me whenever I use my computer outdoors, longer battery life won't really change anything.
Has anyone used both machines before?
My wife has a 13 MBA and I have a rMBP 15". I upgraded from a 13" MBP. All of my bags and sleeves from my MBP fit my rMBP...that's how close the 13" old design is to the new, slimmer retina design even with two more inches of screen.
The rMBP is miles above a MBA and barely larger. I can do a full day's work without a charge.
The question you should be asking yourself is what does the MBA have that you *need* over the rMBP? The screen is the single biggest factor of a laptop. You look at it every time you use the device. Just like you reasoned that you need a good keyboard since you interact with it all the time, so goes the logic for a better screen.
The MBA *was* the better screen because of the resolution compared to a classic macbook pro. But now that retina has come along there should be no contest. The only real consideration is whether you want a 13" or a 15" retina. I can not stress enough how important retina is. In terms of the future the screen is going to last the longest compared to the other components.
The MBA and rMBP both have SSD. Both will likely have 8GB of RAM in your configuration. What are you gaining by going with the objectively lower quality MBA screen? In terms of memory and features, the 15" has a dedicated graphics card that neither the 13" MBA or 13" rMBP have. The future of OS and programs is to make things more efficient...not powerful.
The newest features in Mavericks compress memory on the fly and page unused memory out. I have 16GB of memory on my desktop and struggle to find things to do to fill it up. As in, I often find myself running multiple VM's and leaving games open and making RAM drives *because* I have so much free RAM. Free RAM is wasted RAM.
8GB is sufficient for my 15" rMBP and trends indicate my memory will only become more useful in the future rather than less. That's a strange twist isn't it? Look at the supported devices list that Apple has printed for the upcoming OS X release. They include 2GB MacBooks. Even Microsoft has been doing this with their latest iterations. Windows 7 runs better on older computers and netbooks than previous iterations of Windows. Windows 8 is even more efficient.
The only time bigger is better nowadays is in storage space and resolution/screen sizes. And here's the funny part: the 15" screen isn't all that much larger than the 13" screen. Try it, I did, lay one on top of the other. The 15" bezel is thinner so the total screen size is close (within a half an inch) yet you get much more viewing area.
I love writing papers and grading exams on my retina. The text is clearer, crisper, and I can lay more pages out in front of me simultaneously. And I can write ridonkulously lengthy forum posts with ease...
😉