Keyboard and trackpad
Just to be crystal clear about what we're dealing with here, the MacBook Air is a traditional laptop (or "UltraBook," if you will), while the Surface Pro 2 is a hybrid, or 2-in-1. You'll need to buy a separate keyboard cover for the Surface, so it can transform back and forth between tablet and laptop. The Surface Pro 2 has a terrific built-in (dual position) kickstand, that lets you prop it up in laptop mode.
One big advantage the MacBook has is that its trackpad is much bigger and better than the small one on the Surface's covers. As we'll see in a minute, though, the Surface makes up for that with touchscreen and stylus support.
The Surface Pro 2 is going to leave a slightly smaller footprint in your bag. The MacBook Air is about 11 percent taller, 9 percent wider, and (technically) 26 percent thicker than the Surface Pro 2.
There are, however, a couple of things to keep in mind about that thickness comparison. First, the MacBook Air has a tapered design, and this measurement only counts its thickest point. The Surface doesn't taper in the same way; it's thickness is uniform. You're also going to want to use the Surface with one of Microsoft's keyboard covers, which will add a little extra thickness.
Without a keyboard cover attached, the Surface Pro 2 is 16 percent lighter than the MacBook Air. But that only holds up when you're using the Surface in tablet mode. The rest of the time you'll have a keyboard cover snapped onto the Surface, so this weight comparison is a little misleading.
With the Touch Cover 2 (the light one with non-moving keys) attached, the Surface becomes 1 percent heavier than the MacBook Air. With the Type Cover 2 (the one with physical keys but no battery) attached, the Surface becomes 8 percent heavier than the Air. With the Power Cover (physical keys, built-in battery) on, the Surface becomes 34 percent heavier than the MBA.
Both devices have premium builds. The MacBook uses Apple's favorite, aluminum, while the Surface sticks with the same "VaporMg" (magnesium alloy) construction that we saw in the first Surfaces. The MacBook Air has a physical design that's identical to every MBA since late 2010.
The Surface Pro 2 gives you 84 percent as much screen real estate as the 11-in MacBook Air. The Surface's 10.6-in screen is on the larger end of the spectrum for tablets, and the smaller end for laptops. Having spent a lot of time with the Surface, though, I think Microsoft hit a great display size balance for its 2-in-1.
Display (resolution and pixel density)
The Surface has a noticeably sharper display. Microsoft also employs ClearType (sub-pixel rendering) technology, which makes text look a little sharper on the Surface's screen than its already solid pixel density would suggest.
As a tablet and touchscreen laptop rolled into one, the Surface Pro 2 naturally employs touch. Apple is still insisting that laptops don't need touchscreens. I've spent plenty of time with both Surfaces and MacBooks, and though I agree that traditional notebooks don't need touchscreens, I do think touch is a very nice feature to have in a productivity-based device.
The Surface Pro 2 also includes a Wacom-based stylus. It's great for navigating through those legacy Windows desktop apps, which were never designed for fat fingers. It also allows for pressure sensitivity, and is a great companion for Photoshop (if only Adobe would fix its display scaling issues on the Surface's high-res display).
When you aren't using the stylus ("Surface Pen"), it magnetically snaps into the Surface Pro's charging port. It's also identical to, and therefore backwards compatible with, the Surface Pen from the 1st-generation Surface Pro.
Both devices have Intel's power-sipping Haswell processors inside. The Surface Pro 2's CPU is clocked a little higher.
If you pay Apple extra, though, you can configure the MacBook Air's processor up to a 1.7 GHz Intel Core i7 (with turbo boost up to 3.3 GHz).
The MacBook Air's integrated graphics are a slight upgrade over the integrated GPU in the Surface Pro 2. Both of them will be able to do some light gaming, but don't expect anything close to the horsepower of a gaming PC with a dedicated graphics card.
Both machines are available in both 4 GB and 8 GB RAM options. For the Surface, the 8 GB model is tied to the two largest storage tiers. The MacBook's 8 GB RAM model is a premium configurable option.
Here we have the storage options for each device. The 512 GB MacBook model is also a configurable one that you'll have to pay to add during online checkout.
The Surface Pro has a microSD card slot to help expand that internal storage. If you pony up an extra US$120, you can even pop in one of SanDisk's new 128 GB microSDs. Though it isn't quite the same as having more internal storage, external storage is much cheaper to add to your purchase.
Not only does this 11-in MacBook Air not have a microSD slot, it also doesn't have the full-sized SD reader that you'll find in the 13-in Air.
USB 3.0 port
The MacBook has two USB 3.0 ports, while the Surface Pro 2 gives you just one. You can, of course, buy USB splitter accessories that will effectively give you more ports on either device. But if you want an integrated solution, the MBA has the advantage.
You don't see too many non-Apple notebooks with Thunderbolt ports these days. And you'll still have to pay a pretty penny for any Thunderbolt accessories you want to use. USB 3.0 is going to be the more practical answer for most customers.
The Surface Pro 2 does have a Mini DisplayPort for HDMI out. The MBA's Thunderbolt port is backwards-compatible with Mini DisplayPort cables.
Both devices' Haswell processors help them to have significantly longer battery life than notebooks from a couple of years ago. The MBA's lower-resolution display helps it to last longer (an estimated nine hours of web use), and with typical use I'd say the Surface Pro 2 should last five to seven hours. If you invest in Microsoft's Surface Power Cover, though, then you can stretch its uptimes out by about 30 percent.
The MacBook Air has a 720p webcam, while the Surface Pro 2 has both front and rear cameras.
The MacBook Air runs OS X Mavericks, while the Surface Pro 2 runs Windows 8.1 Pro. Mac OS X has taken on some iOS-like qualities, but it's still a dedicated desktop OS. Windows 8.1 features both the traditional Windows desktop and the new touch-based Modern UI. As much flak as that part of Windows has taken from desktop users, I think it's a great fit for devices like the Surface.
Just to avoid any confusion, the Surface Pro 2 will run all of your old Windows desktop software. If you've heard anyone say that the Surface doesn't support desktop apps, then they were talking about the Windows RT-running Surface RT or Surface 2.
Of course, both machines run any office suites designed for their respective operating systems (as well as web-based suites like Google Docs). But Apple now gives away its iWork suite for free with Mac purchases. The Surface Pro 2 doesn't include Office with your purchase, though you can now rent a license (via Office 365) for as little as $7 per month.
Apple just released this minor update to the MacBook Air earlier this week. The Surface Pro 2 has been around since late 2013.
With the small speed bump, Apple also dropped the MBA's price by $100 across the board. That has it starting at the same $900 as the Surface Pro 2.
Just remember that there's no point in buying a Surface without also throwing down for one of Microsoft's snap-on keyboard covers. The Touch Cover 2 rings up for $120, the Type Cover 2 costs $130, and the battery-extending Power Cover has a $200 price tag. The Surface Pro 2 is also backwards-compatible with the 1st-generation Surface covers, which you might be able to find discounted, though I think the new models are enough of an improvement to warrant the extra cash.
For more on these devices, you can read Gizmag's full reviews of the 11-in MacBook Air (the very slightly slower mid-2013 model) and the Surface Pro 2. You can also hit up our Surface Power Cover review, if you're thinking about tagging that onto your purchase.