Microsoft Surface Pro gets even stiffer competition from new 11.6-inch Apple MacBook Air -- which one would you buy?

To the untrained eye, this comparison appears to be moot. After all, the Surface Pro is a tablet and the 11.6-inch MacBook Air is, indeed, an ultrabook. Traditionally, the two types of devices rarely have anything in common. Tablets offer touchscreens, portability and great battery life while ultrabooks usually fail to deliver the same level of versatility. So how can one pit the Surface Pro against the smaller MacBook Air?

As my colleague Joe Wilcox explained almost seven months ago, the two devices actually have a great deal in common. The Microsoft-branded tablet kicks off at $899, can be coupled with a dedicated keyboard, has expansion ports, runs a fully-fledged operating system and, to its disadvantage, delivers pretty appalling battery life. The Apple-branded ultrabook packs similar hardware specifications, starts at $999 but offers a built-in keyboard from the get-go. And, in the meantime, the fruit company upgraded its device to Intel "Haswell" Core processors which provide a tremendous bump in battery life. Now, more than ever, choosing between the two is a very tough call.

Cha-Ching

Let's tackle the financial aspect first. There are two Surface Pro versions available, with 64 GB and 128 GB of internal storage (excluding the 256 GB Japanese version), which run for $899 and $999, respectively. To get either of the two up to MacBook Air spec, one would also have to shell out $119.99 for a Touch Cover or $129.99 to get a Type Cover (external keyboards).

When paired with a Touch Cover, the 64 GB Surface Pro goes for $1018.99 while the 128 GB model runs for $1118.99. In either case, add $10 to switch to a Type Cover.

By contrast, the new 11.6-inch MacBook Air starts at $999 for the 128 GB model (Apple killed the 64 GB version and replaced it with the aforementioned model). More demanding buyers can also get a 256 GB version which runs for $1,199. And, like previously mentioned, the ultrabook comes with a keyboard out-of-the-box.

Basically, the base 11.6-inch MacBook Air is less expensive than either of the two Surface Pro models, when paired a with dedicated keyboard, and is priced on par with the standalone 128 GB Microsoft-branded tablet.

Muscle-Flexing and Battery Life

The Surface Pro packs a third-generation 1.7 GHz dual-core Intel Core i5 processor backed by an Intel HD Graphics 4000 GPU (Graphics Processing Unit), 4 GB of RAM and a 42 Wh battery.

The base 11.6-inch MacBook Air comes with a fourth-generation 1.3 GHz dual-core Intel Core i5 processor (optional upgrade to a 1.7 GHz dual-core Intel Core i7 processor runs for $150) alongside an Intel HD Graphics 5000 GPU, 4 GB of RAM (8 GB of RAM available as a $100 option) and a 38 Wh battery.

The performance difference is negligible between the base processors found in the two devices, but the 11.6-inch MacBook Air should have an advantage in the graphics department over the Surface Pro (the new Intel HD Graphics 5000 is touted to be considerably faster than the old Intel HD Graphics 4000).

The biggest difference between the Surface Pro and the 11.6-inch MacBook Air is in the battery life department. Microsoft claims between four to five hours of cordless operation while Apple quotes a whopping nine hours of Wi-Fi browsing and eight hours of video playback when relying solely on the built-in battery.

Portability

The two devices are quite similar when it comes to physical dimensions. The Surface Pro comes in at 27.45 x 17.3 x 1.35 cm and 916 grams while the 11.6-inch MacBook Air measures 30 x 19.2 x 0.3 - 1.7 cm and weighs 1080 grams. The former is slightly shorter, narrower, thinner (overall) and lighter than the latter.

But pair the Surface Pro with a Touch Cover, which adds 3 mm in thickness (1.65 cm overall) and 210 grams in weight (1126 grams total), and two of the advantages it has, as a standalone device over the 11.6-inch MacBook Air, disappear (Surface Pro remains shorter and narrower still). The Type Cover is even thicker (comes in at 5.8 mm) and heavier (weighs 218 grams) when compared to the Touch Cover.

Touchscreen vs Touchpad

Surface Pro packs a 10.6-inch 10-point multi-touch display with a resolution of 1920 by 1080 and a ppi (pixels per inch) density of 207.82. By contrast, the smaller MacBook Air features a bigger 11.6-inch screen which has a lower resolution of 1366 by 768, a ppi density of 135.09 and forgoes touch input.

Because it offers a touchscreen, the Microsoft-branded tablet can be used without a dedicated keyboard or mouse. The device also comes with a stylus which makes it more suitable for drawing and taking notes, for instance. By contrast, touch input on the 11.6-inch MacBook Air is limited solely to its gesture-friendly touchpad.

The Other Bits

The Surface Pro also offers: two 720p cameras (front and rear); Wi-Fi 802.11 a/b/g/n; Bluetooth 4.0; USB 3.0 port; microSDXC card slot; MiniDisplay port; ambient light sensor, accelerometer, gyroscope and magnetometer.

The 11.6-inch MacBook Air also packs: 720p front-facing camera; Wi-Fi 802.11 a/b/g/n/ac; Bluetooth 4.0; two USB 3.0 ports; Thunderbolt port; MiniDisplay port; ambient light sensor and backlit keyboard.

The differences: Surface Pro offers one more camera, a microSDXC card slot and more sensors while the 11.6-inch MacBook Air features faster Wi-Fi connectivity, one more USB 3.0 port, a Thunderbolt port and a backlit keyboard.

The Software

Undoubtedly, this is a matter of personal preference. The Surface Pro runs the 64-bit Windows 8 Pro while the 11.6-inch MacBook Air ships with OS X Mountain Lion. The latter can also run Windows 7 or Windows 8, natively, through Boot Camp. That said, each operating system has its own advantages and disadvantages and what works for one user may not work for another, and vice-versa.

Still, the questions remain --  Which one would you buy? And, which one better fits your needs? Please explain in a comment below.