To compare, I can tell a little difference when comparing my 2013 MBA vs my mate's MBP Retina. Is it worth the reduction in battery life? I'd say no.
I never have to worry about the Air's battery life, and it is so thin and nimble. I carry it in my rucksack and I can't feel it's there at times.
If you're travelling a lot, it has to be the MBA for me. I really don't see how people make such a big deal over the screen.
You only way for you to decide is a trip to the Apple shop, or nearest computer store. I'd only buy direct off Apple online's student store so you get the 3 years warranty included.