The new MacBook Air models has the latest Intel Haswell processor, new Intel HD Graphics and PCIe flash storage.
Besides screen size, the specs for the four latest MacBook Air machines are similar and share the same processor in succession at the same clock speed and all feature the same graphics. The only preference other than size is how much storage you want: 128GB or 256GB, with both options available for each laptop.
Only the 13-inch model has an SDXC card slot so if you are an avid photographer that may be a factor.
There is little distinction when it comes to the speed and power of the 11-inch and 13-inch MacBook Airs. The differentiating option is storage. Choose between 128GB and 256GB on each model. Or pay an extra £240 for 512GB as a build to order option.
If you want a laptop with a good battery then the 13-inch MacBook Air could be a good choice. If you’d prefer lighter hand-luggage then the 11-inch could be more than adequate.