Like I said here previously, on a power-to-weight-and-volume basis, the MBA is one of the most powerful machines Apple makes.The MBA is a marvel -- consider the fact that it is only 40% of the size of an MBP.
If you had to compare the various Mac desktop and notebook models to cars, the MBA would be like a Lotus Elise... a small two-seater with a high power-to-weight ratio and no trunk to speak of. It ain't an SUV, it ain't a coupe, and it ain't a supercar like a Ferrari or a Lamborghini.