Shortly after Apple’s (AAPL) iPad 2 launched, my mother called me asking for advice. She had been reading about the iPad’s improvements and new apps, and determined it might just be powerful enough to replace her laptop. I asked her what she wanted to use it for and which programs she used the most. By the end of the discussion, we determined that the iPad would not be suitable for her as a laptop replacement.

You can visit any Best Buy and walk around the laptop section, and you’re likely to hear this same question posed to sales associates multiple times per day. The debate over a laptop or tablet is a justified one. Apps and the tablets on which they run have become more powerful. The line between the two devices continues to blur.

Microsoft (MSFT) believes this a problem to be solved. “Today, we take the conflict away and I’m absolutely sure of that,” declared executive Panos Panay on stage during the May 20 introduction of its new tablet computer. “I’d like to introduce you to Surface Pro 3.”

This is a remarkable statement. Microsoft has positioned its new device as a replacement for the Windows laptop as well as the iPad and its Google Android-powered peers, even as sales of previous versions of the Surface have fallen flat.

Anyone can talk the talk; I decided to take the Surface Pro 3 for a walk. A very, very long one: With Panay’s declaration still fresh in mind, I took a week-long trip to Japan with the Surface Pro 3 in tow. To fairly assess its abilities, I left my MacBook Air at home.

It was the first time I had traveled without my MacBook Air on a business trip, let alone one to a foreign country. I was nervous.

Microsoft worked hard to put the Surface Pro 3 on a diet. It’s slightly more than a third of an inch thick and weighs 2.4 lbs. with the Type Cover click-in keyboard attached. To put that in perspective, Apple’s MacBook Air weighs slightly less than 3 lbs. and is just over two-thirds of an inch at its thickest point.

Microsoft redesigned the latest Surface, but more notably, the company also redesigned the Type Cover, which includes a standard keyboard and a trackpad. During my marathon flights to and from Japan, I put the Type Cover to task: I passed the time by typing emails and short stories. I moused around using only the trackpad. I found the keys on the cover to be responsive and well spaced, but extremely noisy. And the trackpad? Nothing short of finicky. At times it would register a two-finger tap—which triggers a right-click action—when I only had one finger on the pad. With the omission of an option to disable tap-to-click in Windows 8.1, there seems to be no clear way to avoid the accidental right-clicks I found myself unknowingly causing.

A new “friction-hinge” kickstand on the back of the Surface makes it possible to adjust the tablet’s viewing angle to suit your needs, an improvement over previous versions, which allowed only one or two viewing angles. You can nearly lay the Surface down by placing the hinge at a 150 degree angle, which I found to be a comfortable position for using the Surface Pen to sketch or take notes. Be forewarned: The kickstand setup does require a bit more room to implement, so if you’re planning on using the Surface and Type Cover on a fold-out tray table in economy class, you may find yourself hard-pressed for room. Even in the Business First cabin, I was left with precious little space. On more than one occasion, the back of my Surface setup slipped off the rear of my tray. (Apple’s iPad has no built-in kickstand, but several third-party companies make cases and stand-like accessories for it.)

Oh, and about that Surface Pen I briefly mentioned above. Microsoft claimed it put a lot of work and effort into mimicking the experience that a classic legal pad and pen provide, and it’s one reason the company chose a 3:2 aspect ratio over the more-common 16:9 found on other tablet computers. In practice, I found the Surface Pen to write more smoothly than any other stylus I have ever used. During meetings, I eschewed the clickity-clack of the keyboard and instead used the pen with OneNote. I found myself nearly forgetting that I was writing on a digital surface—my digitized handwriting reflected exactly what I would expect on a piece of paper. The analog-to-digital translation was uncanny enough that people sitting around me asked me how to mimic the experience on an iPad.

“Lapability” is a term coined by Panay and his team in an effort to underscore that the Surface Pro 3 is fully capable of playing in the laptop’s namesake environment. It’s a direct appeal to address a market in which sales of traditional PCs (which include laptops) are plummeting and sales of mobile devices (which include tablets) are rising.

During my trip, I tested out the Surface on every mode of transportation I encountered: airplane, train, and automobile. (A portion of my trip involved a boat, but I wasn’t brave enough to take the review unit along with me.) For the most part, it’s possible to use the new Surface in your lap with the Type Cover attached, though I found some positions where the unit would move excessively while I typed, forcing me to adjust how I was sitting or how the device was placed in my lap. This “reposition dance” is something you don’t really have to do with a laptop. While the Surface Pro 3 is technically “lapable,” it’s hardly enjoyable to do so.

The most important aspect of a tablet is the software. The Surface Pro 3 comes running Windows 8.1, which offers a modern app-centric user interface as well as the classic desktop view. More options would appear to be better, but reality says otherwise: the app-centric side of the operating system still lacks a robust library of native Windows 8 apps, forcing you to the desktop side in search of capability. For Microsoft, it’s a shame: even though the company provides a mobile-first environment for developers, they lack sufficient incentive to develop for it.

Which leaves only the classic desktop interface. Though you can use a finger to touch and tap around the environment, it isn’t a pleasant experience. A combination of small touch targets and stubby fingers leaves you trying multiple times to press a button on screen, for example, or tapping on the wrong item and ending up in another app or on a different web page than you intended. An example of this excruciating experience was when I tried to view photos in File Explorer; I found myself tapping on folder icons multiple times in despair, hoping one would eventually open. Sometimes I became so frustrated that I would connect the Type Cover to complete the task. (Don’t get me started on what it took to open individual photos.)

After a week abroad and almost 12,000 miles in the sky, is the Surface Pro 3 a suitable replacement for my laptop? Not quite. I found it to be capable but frustrating in its inconsistency. That broken experience hinders Microsoft’s ability to compete with Apple in the tablet category. Microsoft promised to eliminate conflict with the Surface Pro 3, but Windows 8.1 is full of it.

True to Microsoft’s word, the Surface Pro 3 can replace a laptop. Whether you’d want it to, well, that’s another story.

Microsoft has begun taking pre-orders for the Surface Pro 3 at its website. The device starts at $799 and some models will ship as early as tomorrow.

“Logged In” is Fortune’s personal technology column, written by Jason Cipriani. Read it on Fortune.com each Tuesday.