For the most part, Surface Pro 3 excels on the road. This is a thin and light travel companion that can keep up with the best Ultrabooks on the market and do double duty as an entertainment tablet, offering several hours of battery life and a great looking screen.

As I noted in Surface Pro 3: Portability, Surface Pro 3 is bigger than its predecessor, but it's also quite a bit thinner and lighter than Surface Pro 2. And my early assumption about the overall portability of this device has held up over two trips now: I try to travel as lightly as possible, and the carryon for this latest trip is perhaps my lightest ever. My bag seems half-empty.

On the bumpy train ride home from New York City two weeks ago, I noted how Surface Pro 3's built-in kickstand really helped with stability. While my wife's Ultrabook screen bobbled with the movement of the train—sometimes riding on Amtrak is like being on rough seas, thanks to the poor quality of some tracks in the Northeast corridor—Surface Pro was rock solid.

That's neat if you travel by train. But I was curious to see whether Surface Pro 3 would even be usable on a plane. My current trip is a good test: JetBlue uses smaller A320 planes between Boston and Denver, so the tray table is about as small as they come on a mainstream domestic flight.

On the other hand, I also upgrade to "Even More Space" seats in an exit row to maximize the distance between me and the seat in front of me. This usually lets me get work done.

Surface Pro 3 tested the limits of this arrangement. The innovative Type Cover is excellent and provides a good typing experience in general. But in the cramped quarters of the A320's tray table, the Type Cover hung out over the front edge by about two inches, even with the kickstand in the first, most upright position.

It worked. But I also couldn't really rest my wrists on the Type Cover's wrist rest because doing so would push down on the front of Type Cover, lifting the back, and thus lifting the bottom of Surface Pro 3 off the tray tablet. Not good.

I was able to write about an article and a half in the first two hours of the flight working with my wrists only lightly resting on the Type Cover wrist rest, but as pain started edging into my left upper hand, I realized this wasn't ideal and figured I should mix up the usage between work and videos in order to give my wrists a rest.

(This is why I use an ergonomic keyboard at home and a large mouse at all times: These devices save my wrists from carpal tunnel or whatever other issues. They have literally saved my career.)

While doing this, I monitored the battery life, which I know is an ongoing concern for many. I had shut down the device before leaving home, which is something I don't normally even consider, but given the temporary pre-release power management issues, I felt this was prudent. (All I had to do was imagine getting on the plane and having a dead battery.)

The flight to Denver had Wi-Fi, which I enabled and used. I had several applications open the whole time, including Microsoft Word, Chrome, Mail, Photoshop, and others, and I used Xbox Music to stream music over Wi-Fi while I wrote. I even published an earlier article from the plane, while somewhere over South Dakota, I think.

After two hours of use, the battery was at about 65 percent and reported 3 hours and 30 minutes of life remaining. This wasn't particularly reassuring, but I also hadn't taken any steps to dim the screen or whatever, as I try to rely on default settings during my earliest device tests. But this seemed wrong, so I dimmed the screen a little, fired up a movie (in this case an SD DVD rip) and let my wrist breathe for a bit.

(I noted in Surface Pro 3: Battery Life, Part 1 that Microsoft will soon issue a fix for some wonky power management-related issues in this device, and I suspect what I was seeing there is related. It just doesn't function as you'd expect. The good news? Surface Pro 3 hasn't even shipped publicly yet, and this seems like the type of thing that can easily be fixed. Regardless, it's easy enough to customize a power management profile.)

90 minutes later, the battery was at 48 percent, but was still reporting 3 hours and 30 minutes of life. Now that's more like it. I started writing again but—bing!—the flight was landing and it was time to stow the big electronics.

Working from the hotel room later, I was able to begin what I think is a second crucial step in testing a portable device: Actually using it, and only it, away from the comfort of home and the reassurance that, should anything go wrong, you have other machines to fall back on. I only brought Surface Pro 3 with me on this trip—no backup Ultrabook or whatever—along with a few phones, cables, and other assorted electronics.

I find with some machines that the limitations can be confining. I love the ThinkPad X1 Carbon, for example, but had a weird stumbling block with the lack of a dedicated PRINTSCREEN key since I use that so often. (As it turns out, there is a hidden key combo for that.) When I use smaller screen devices, I miss the onscreen real estate. Many devices have lackluster keyboards. There are all kinds of things that can compromise your experience.

Surface Pro 3, both from home and now on the road, of course has its own compromises. I really feel that Microsoft blew it by not including a second USB port, most obviously, and I'll be using my Diamond USB 3.0 hub with gigabit Ethernet when I head into the office. But many of the things I thought would be issues—so far at least—are not.

For example, the keyboard on the Type Cover, while a bit less wide than the keyboard on a typical Ultrabook, is surprisingly OK. I hit the CAPS LOCK key a bit too often, and I of course set the mouse cursor in motion inadvertently when my wrist hits the trackpad while I'm typing, but neither issue is unique to this device. Using Surface Pro 3 on a desk, I prefer to use the Type Cover flat, not angled up against the screen, and I can't explain why, but it just feels right when typing. It really isn't horrible at all. I'll keep watching my wrists, but so far so good.

And the screen, while small by Ultrabook standards, has really won me over, thanks to its 3:2 aspect ratio, which just works in ways that are hard to describe, and the high pixel density, which makes text much crisper and easier to read.

Compromise is a misunderstood word, just as bias is, and it has negative connotations that are not necessarily deserved. The compromise here, so to speak, is the balance between efficiency, power, utility, and portability. And it's a compromise Surface Pro 3 handles deftly. I mean, look how cute this thing looks in a plane's seatback pocket.

And yet it's a real PC. It runs real Windows, with real desktop apps. And it has a powerful Core processor with lots of RAM and storage. I can and do use Hyper-V with this device, and Visual Studio. Photoshop. And full Office. These are huge advantages. But they come with little in the way of, well, actual real-world compromise.

Anyone who carries around a PC, anyone who travels with a PC, needs to consider these compromises. And while some people can get work done with a tablet or even a smart phone—maybe I should have written that as "work"—for those of us with actual productivity needs, only a PC will do. So the goal as always is to get as much utility as you can from a device, a PC, which is likewise as portable as possible.

Surface Pro 3 makes a compelling case for being that device. I'll see how it stands up to a week away from home before really deciding, but I may have found my next portable PC. It's that good.