That's because Apple has slowed the processor down this year, from 1.8 GHz to 1.3 GHz, in order to achieve the one major improvement in this year's model: the battery now lasts all day.
Apple advertises you'll get 12 hours of usage between charges with the 13-inch model. We got a shade under nine hours in our formal tests (up from six hours from the 2012 model) but I'm getting more like 15 hours of usage per charge in practice.
The Haswell is really, really good at quickly shutting itself down when it's not being used, and when you don't use the machine absolutely constantly, the battery life just goes on and on.
I'm noticing a few other changes, apart from the battery life. Some time in the past two years, Apple seems to have introduced a bug into its Mac OS operating system, that causes the MacBook Air to go to sleep just moments after it's woken up. It's happened to me five or six times now. It's not a big deal - it's not crashing, so I haven't lost any data or anything - but it is a little frustrating. Hopefully it will be fixed in September, when Apple is due to release the next big upgrade to its operating system, known as the Mavericks upgrade.
Mavericks will have some decent changes in it, such as the inclusion of Apple Maps (which mostly just works nowadays, despite its embarrassing start) and a lot of power-saving features, such as turning apps off when they're not visible, which should stretch the Air's already impressive battery life even further.
Hopefully I'll still be reviewing Apple products come September, so I can review Mavericks and see what it does to the battery life. I've very much enjoyed this little trip back into Apple land. It's wrong, but it feels so right.
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