Sony and Apple have been longtime rivals in the premium consumer-electronics world, with both manufacturers setting trends and making fashion statements while pushing the boundaries of technology.

The companies now clash once again, each with flagship products in a category that pushes the envelope of form and function: the ultraportable-class notebook computer.

Apple's Macbook Air has defined avant-garde since its introduction in 2008. The latest iteration follows that tradition, sporting a sleek thin aluminum frame, a full-sized keyboard and screen, with no moving parts.

Not to be outdone, Sony also introduced the latest to its Vaio Z line, its answer to the Macbook Air and every other ultraportable this July. Featuring a carbon fiber and aluminum body and hardware typically reserved for desktops, Sony aims for brains as well as beauty.

First, a quick look at the specifications:

13.3-inch Vaio Z:

Chassis: 0.66 inches thick, 2.5 pounds, carbon fiber

Graphics: Internal Intel Ivy Bridge, (external AMD 6650M GPU)

Processor: Ivy Bridge Core i5, i7 standard voltage

Storage: solid-state drive only, up to 512GB

Connector: Light Peak, aka Thunderbolt, and USB 3.0 on dock

Broadband: N/A

Display: 13.3-inch, 1920x1080 resolution

Battery: internal battery rated at 7 hours

OS: Windows 7

Price: Standard Configuration $1,600.

13.3-inch MacBook Air:

Chassis: 0.68 inches thick, 2.9 pounds, aluminum

Graphics: Internal Intel Ivy Bridge

Processor: Ivy Bridge Core i5

Storage: solid-state drive only

Connector: Thunderbolt*

Broadband: N/A

Display: 13.3-inch, up to 1440x900 resolution

Battery: internal battery rated at 7 hours

OS: OS X Lion

Price: Standard configuration $1,199

Aesthetics

The first Macbook Air boasted being the world's thinnest laptop at the time of introduction. In fact, Apple CEO Steve Jobs took shots at Sony's then flagship Vaio TZ, saying the thickest parts of the Macbook Air is thinner than the thinnest part of the Sony. Today that distinction is no longer true.

Sony's Z is not only thinner than the MBA, it's even lighter, beating it out by 0.3 pounds. Apple's offering is a wedge-shaped design, so as the chassis tapers toward the front it becomes much thinner.

The Sony features a carbon-fiber lid familiar to Z users of the past, but boasts an aluminum body time around, giving the unit two exotic materials, but perhaps lacking the uniformity of the MBA. In fact, the all metal chassis of the MBA makes the Sony feel fragile and weak in comparison. And Sony's design is rather muted. Unlike the head-turning Macbook Air, Sony's slim chassis features subtle design cues that won't excite many.

Conclusion: The muted design of the Vaio won't have mass appeal but will hold authority in a boardroom. The MBA, while its 4 year old general design is starting to age, it's still the most stunning, durable laptop on the market.

Mobility

With both units weighing less than 3 pounds, both are effortlessly easy to carry around. Both also have identical battery life, though in our tests the Sony lasted for roughly 5.5 hours -- about 1 hour less than the Macbook Air.

All in all both units are fantastically mobile. For your typical consumer, there isn't much difference here. But for a mobile professional, the nuance speaks loudly.

The Vaio Z has optional wireless wide-area network capability (in the Asia and Europe as of this writing), letting users log on to cellular networks, for instance, to access Internet virtually anywhere. More over, Vaio users can purchase a sheet battery that attaches to the bottom of the unit, surging battery life up to an unprecedented 15 hours -- more than 50 percent longer than the energy-sipping iPad.

The hardware inside the Vaio Z can tend to run hot, however, and the dual fans on the bottom can make for a toasty lap and a loud notebook, depending on what tasks are running. This may not make for polite company, depending on the setting. It's worth noting that Intel gives both Sony and Apple a hand in this department, with its new i7 line being built on a smaller 22 nanometer manufacturing process. The smaller transistors means both units run longer and cooler than predecessors.

In comparison, the Macbook Air runs cool and quiet for the most part. One area where the MBA stands out is the ingenious speaker technology. Utilizing a sonically optimized enclosure, the Macbook gets loud and sounds good for its size, whereas the Sony's speakers are some of the worst on the market.

The Macbook also has the best track-pad on the market, built to take full advantage of OS-X's gesture recognition, making navigating through programs a breeze. The longer battery life will let you work longer as well.

Where the MBA fails is in the department of connectivity. The lack of any broadband option may or may not be an issue for many, but the lack of standard ports is definitely a burden. Your small, lightweight package is mired by the fact that you'll need to also carry a dongle for Ethernet or HDMI.

Conclusion: Typical consumers can get enough done on the road with either. With the 3rd generation i5 processor the MBA is a solid performer and has enough horsepower for most task you'll find yourself in, but for the more demanding, performance-based mobile professional, the Vaio Z wins.

Performance

Both the Macbook Air and the Vaio Z are built on top of Intel's Ivy Bridge architecture, giving them both the latest processor technology, among other things. But they differ in one very important detail.

The Macbook Air uses a low-voltage version of Intel's i5 processor. This is typical for thin, light notebooks. But through the miracle of modern engineering, Sony was able to squeeze a full-powered i5 or i7 processor into the diminutive body.

As noted above, this makes for a slightly hotter, noisier experience, but the performance rivals that of desktop computers. Simply put, there's no faster ultraportable, and this Z would give even a few desktops a run for their money.

Sony throws in a special Power Media Dock that integrates an optical drive with an external graphics card, letting users run high-end graphics applications across up to three monitors -- including the built-in display. The unit is optional this year, bringing the price of the unit down by $400.

Both units come with solid-state storage, making the boot process and software load incredibly quickly, and users won't need to worry about damaging the hard-drive in rough conditions. Sony however deploys something called Raid 0, which essentially stores data across two separate drives, making reading and writing theoretically twice as fast.

Conclusion: The Vaio Z wins hands-down in performance. From processing, to graphics -- and even the screen packs more pixels than the MBA's already first-class display (and an optional full HD screen), there is no comparison.

All in All ...

When the Macbook Air was first introduced in 2008, Jobs said that Sony and other manufacturers made too many compromises as they sought to make something light and portable.

With the arrival of the flagship machines from both manufacturers, it would appear that Apple is now the one making compromises.

With the Sony Z users can basically get a desktop replacement that weighs under 3 pounds and is the lightest notebook on the market.

he drawback is you'll have to pay for it. While no longer bundling the Power Media Dock dropped the base price of the Vaio, it still starts at $500 more, and even up to three times the Macbook Air in certain configurations, but for those with demanding requirements that need the best in mobile computing, the Sony Vaio Z is IBT's choice.