Microsoft had a lot riding on Surface. But the initial Windows RT version – with its hybrid OS and limited app selection – has hardly transformed Redmond into a serious player in mobile. That leaves Steve Ballmer and company pinning their hopes on the Windows 8 Pro Surface. Does its full-fledged desktop OS make it a better buy than its cheaper predecessor? Read on, as we compare the specs – and other features – of the Surface RT and Surface Pro.

Size

At first glance, you might think the two tablets are identical. Surface Pro is slightly wider than Surface RT, but the biggest difference is its extra 4.1 mm of depth.

Weight

Surface Pro is one heavy tablet. Surface RT was already one of the heavier 10-inch tablets, but its Pro cousin outweighs it by 227 g (8 oz).

Display

The Pro version has a much sharper display than its ARM-based cousin.

Surface RT’s ClearType (sub-pixel rendering) technology made its sub-par resolution look better than it could have. Surface Pro packs more pixels, but still retains ClearType. You aren’t likely to have many complaints.

Processor

Performance-wise, Surface Pro blows Surface RT out of the water. There are other tradeoffs, but its processor puts it more in the class of a MacBook Air or Ultrabook than an ARM-based tablet.

RAM

Surface Pro’s RAM is also more in the ballpark of laptops than other tablets. Its 4 GB of RAM doubles the RT model’s 2 GB.

Storage

On paper, Surface Pro comes in 64 GB and 128 GB models. But the usable free space will be much less (29 GB and 89 GB, respectively). Surface RT’s usable storage also takes a hit, at about 16-18 GB less than the listed total.

Wireless

Microsoft isn’t selling either tablet in 3G or LTE models. If you want mobile data, you’ll need to either tether your smartphone or plug in a USB wireless hotspot.

Battery

Surface Pro has a higher-capacity battery, but its more powerful processor takes a hit on battery life. It should last 3-4 hours, compared to the RT version’s 7-8 hours.

Camera

Don’t expect much in the camera department. Microsoft is mum on the cameras’ megapixel counts, only describing them as 720p.

Price

Surface Pro has MacBook-like horsepower, but it also has a MacBook-like price tag. With a US$899 starting price, Microsoft may have a hard time selling customers on its Windows-running tablet.

If you want to add Surface's keyboard, you'll need to fork over at least another $120.

Intangibles

Microsoft’s motto for Surface is “no compromises,” but both tablets have big tradeoffs.

Surface RT is lighter and thinner, with solid battery life. But it only runs Windows Store apps. The selection pales next to iOS’ App Store and Android’s Google Play.

Surface Pro runs desktop apps and performs like a laptop, but it has miserable battery life, is thick and heavy, and – with its keyboard – costs as much as a MacBook Air.

Each device has an audience, but neither is remotely uncompromised.

Wrap-up

Despite the physical resemblance, Microsoft’s two tablets are polar opposites. In several years, Redmond may sell a thin, light, tablet that runs desktop apps and performs like a laptop. Until then, you’ll have to pick your favorite mixed bag.