I was initially quite impressed with Apple's newest MacBook Air after just a few days of use -- and now, after having used this ultra-svelte 13-in. laptop for the better part of a month, this little machine has managed to consistently wow me with its extended battery life and better-than-expected performance. In many ways, the MacBook Air sits in the sweet spot between portability and power, with more than a dash of style thrown in for good measure.

When it comes to style, the new model looks exactly like its predecessor, except for a tiny second microphone hole on the left side. This year's changes are all beneath the surface -- and are uniformly good, unless you happen to be a user who likes do-it-yourself upgrades.

The MacBook Air line-up

The latest Air line-up, unveiled last month at Apple's Worldwide Developers Conference, is powered by Intel's fourth generation dual-core "Haswell" chip. The Core i5, which is the standard processor offered with the new Air, is specifically designed for low power consumption, sporting 3MB of shared L3 cache and clocked at 1.3GHz (it can ramp up to 2.6GHz when needed for processor-intensive tasks).

All of the Airs come with 4GB of 1600MHz LPDDR3 SDRAM (upgradeable to 8GB); an Intel HD Graphics 5000 series integrated graphics chip that offers dual-display, extended desktop support; and the ability to use the next-generation Wi-Fi standard, known more technically as 802.11ac.

The line-up also comes standard with a built-in FaceTime HD camera (for video chats and PhotoBooth); a large Multi-Touch glass-covered track pad; a full-size, backlit keyboard; decent-sounding stereo speakers; a solid magnetic latch; two USB 3.0 ports; dual microphones (for noise canceling purposes); a headphone jack; a Thunderbolt port; and the MagSafe 2 power port, which automatically disconnects the power cord from the computer if suddenly yanked out.

The basic $999 model is equipped with an 11.6-in. 1,366-x-768-pixel, LED-backlit display; 128GB of flash storage and a battery capable of nine hours of estimated battery life (according to Apple's tests). For another $200, you can double your storage to 256GB. The smallest Air weighs just 2.38 lb., is 11.8-in. wide and 7.56-in. deep. When closed, it's just 0.11 in. at its thinnest point and 0.68 in. at its thickest.

The MacBook Air line comes in two sizes, one sporting an 11.6-in. display, the other with a 13.3-in. screen. (Image: Apple)

The model I worked with -- provided by Apple for review purposes -- was the entry-level 13.3-in. (1440-x-900-pixel) MacBook Air, which sells for $1,099. This version comes with an Intel Core i5 chip, 128GB of flash storage, 4GB of RAM, an SDXC card slot, and up to 12 hours of battery life (also based on Apple's own tests). While has the same height as the smaller air, it is 12.8 in. wide, 8.94-in. deep and weighs 2.96 lb.

There are a variety of build-to-order options, including an upgrade to a 1.7GHz Intel Core i7 chip, to 8GB of RAM and to more flash storage -- as much as 512GB for an additional $300 (this last option can only be applied to the $1,199 11-in. model and the $1,299 13-in. model). A totally tricked-out 13-in. Air goes for $1,849.