iPad Pro with Apple Pencil. Image source: Apple.

Last week, Apple (AAPL 0.52%) finally unveiled its long-rumored iPad Pro, a larger version of its flagship tablet sporting a 12.9-inch display. At the same time, you can't ignore the similarities to Microsoft (MSFT -2.45%) Surface Pro 3. Both tablets start at $799, and buyers are half-expected to purchase the extra stylus and keyboard covers on top to truly unlock full functionality. With that in mind, how do the two tablets stack up against each other?

A tale of two tablets
Let's start by looking at the entry-level specs to see what you get for $799.

Specifications for $799 model

iPad Pro

Surface Pro 3

Display size

12.9-inch Retina display

12-inch ClearType Full HD Display

Display resolution

2732 x 2048

2160 x 1440

Storage

32 GB

64 GB

Processor

A9X (speed unknown)

Intel i3-4020Y 1.5 GHz

Rear-facing camera

8-megapixel

5-megapixel

Front-facing camera

1.2-megapixel

5-megapixel

Operating system

iOS 9

Windows 10

Touch ID

Yes

No

Source: Apple and Microsoft stores.

There are a couple of other points of consideration when it comes to the accessories. Surface Pro 3 comes with a Surface Pen included ($50 when purchased separately), while Apple Pencil is sold separately for $99. Apple's new Smart Keyboard cover is also more expensive at $169, compared with Microsoft's $130 Type Cover. Assuming you want both the stylus and the keyboard cover with the entry-level model, Apple's total comes to $1,067, while Microsoft's total comes to $929.

Surface Pro 3 with Surface Pen. Image source: Microsoft.

It's worth pointing out that Apple's A9X chip offers incredible performance. Since the device was just announced, no official benchmarks have been released, but there should be no doubt that the A9X trounces the i3-4020Y in the entry-level Surface Pro 3. Here's our resident semi specialist Ashraf Eassa:

Although I would caution against putting too much faith in a single performance test, it's worth noting that in the popular Geekbench 3 test, the Core i3-4020Y found inside of the Surface Pro 3 scores roughly 1564 points in the single-core test and 3230 in the multicore test. The previous generation Apple A8X, on the other hand, scores around 1800 points in the single core subtest and 4500 points in the multicore subtest.

The A8X is already faster here, meaning that the A9X in the iPad Pro -- which Apple says delivers up to 80% more performance than the A8X -- should pull even further ahead.

Buying a faster Surface Pro 3 model that's comparable to the iPad Pro's processor negates the price advantage that Surface Pro 3 has with its base model.

The iPad Pro comes in only three configurations, making it a little bit simpler. A higher 128 GB storage-capacity model costs $949, and a 128 GB model with 4G LTE cellular data connectivity costs $1,079. Microsoft offers a total of five configurations, featuring different processors, RAM, and storage that make the decision more nuanced. The most expensive Surface Pro 3 costs $1,799 and gets a Core i7 with 8 GB of RAM and 512 GB of storage.

However, one weakness in comparing the iPad Pro to the Surface Pro 3 is that the Surface Pro 3 was launched in the summer of 2014, and Microsoft is expected to refresh the Surface Pro, potentially even as early as next month.

The deal-breaker
Ultimately, the difference in specs is unlikely to sway any potential customer's purchase decision. The biggest difference between the two devices is obviously the operating systems they run. This contrast cannot be understated, since Apple and Microsoft have taken dramatically different strategic approaches with how they architect their interfaces and what types of software applications they support.

It's important for Microsoft to support all of its legacy x86 applications, which provides a sort of continuity with the past. Windows 10 also includes distinct tablet and desktop modes, which are optimized for touch input and keyboard/mouse input, respectively. iOS, on the other hand, has been built from the ground up for touch input, and Apple decidedly broke free from the past when it came to apps.

This should be the deciding factor. Hardware aside, do you prefer Windows 10 or iOS 9?