We also found that the new Intel graphics sped things up 24 percent on the 11-inch compared to last year's model. You can also expect to see 8 percent higher frame rates in games like Portal 2.
So as you can see, there is little difference when it comes to the speed and power of the 11-inch and 13-inch MacBook Airs. The differentiating option, other than the obvious, is storage. Choose between 128GB and 256GB on each model as standard, or pay an additional £240 for 512GB as a build to order option. We'd recommend that you save your money and spend it on external storage. You'll get more for your money that way.
The other decision will be over RAM. All the machines come with 4GB as standard but we'd recommend you boost that to 8GB for an additional £80 at time of purchase. Since these machines aren't upgradable you may regret it in a few years time if you don't max out your RAM now.
The battery-life benefit
Because Haswell is less power hungry, longer battery life is possible. As much as 12-hours in the case of the 13-inch model, according to Apple. Our battery tests suggested slightly less at 8 hours 18 minutes for the 13-inch, but that's still 36 percent longer than last year.
Battery life is the other big difference between the two MacBook Air models - Apple says that the 11-inch offers a nine hour battery - our tests suggest around 6 hours 6 minutes, which is almost double that of last year's.
For many longer battery life will be at the top of their wish list when choosing a new laptop. Most of the laptop owners we know complain that they don't get enough battery life out of their portable, and the popularity of the iPad with its 10-hour battery has lead many to start to expect the same of their laptop.
If you want a laptop you can take on a long-haul flight with a battery to match then the 13-inch MacBook Air will be a great choice. If you have a slightly shorter flight and you'd prefer lighter hand-luggage then the 11-inch will be more than sufficient.
Which MacBook Air?
Battery life aside, the choice between the two identically speced models really is just a matter of screen size verses weight. Either you're prepared to carry 270g of extra weight for a slightly larger screen, or you aren't. We've been using the smaller MacBook Air for a week now and we'll admit that the 11-inch screen wasn't nearly as cramped as we expected and was a worthy tradeoff for being able to throw the laptop in a bag and carry it around without feeling weighed down.
Sign up for CIO Asia eNewsletters.