I would get the macbook air, but mainly because it is unix underneath, so (1) security is solid, (2) there is a ton of freeware/open source analysis tools for it, and (3) the air is super light and rugged which makes a huge difference when traveling. The other issues mentioned by 28b2... who cares.
you can spend the same money and get much better configuration. if you want unix, install linux.
mac being better is just a myth. people compare low end windows with high end macs. compare apples to apples and you will get a lot better value for your money.
anecdotal evidence: i once owned a macbook for three years. the hard drive crashed three times (once in each year). my all other (5) laptops are/ were non-apple based and never had this trouble.