Google's Project Tango is now the consumer-ready Tango, arriving with the launch of the Lenovo Phab2 Pro. But just how much appeal does an indoor-mapping, AR-experience-creating smartphone have to consumers? While that remains to be seen, it is clear that Google and Lenovo have some impressive tech baked into this whale of a phone.

The Lenovo Phab2 Pro is a seam-busting device that's going to test the limits of your jeans pockets. At 180 mm (7 inches) tall and 89 mm (3.5 inch) wide, it comes out at 18 percent taller and 17 percent wider than the Galaxy Note 5 (already a pretty big phone). Its 6.4-inch screen is enormous too, giving you 15 percent more real estate than the also-enormous Nexus 6. The Phab2 Pro is basically a tablet posing as a smartphone.

If you still need convincing, here it is next to the (5.5-inch) Galaxy S7 edge I had with me in the demo area:

On the other hand, a phone that big has room for a big battery – and Lenovo seized that opportunity. The Phab2 Pro's is 4,050 mAh, which is 47 percent higher-capacity than the battery in the iPhone 6s Plus. Lenovo is estimating 18 hours of talk time – and a Googler I chatted with volunteered, unprompted, that "its battery life really is impressive."

Looking at the Phab2 Pro as merely another smartphone, this would be a gigantic tablet/phone hybrid, with quite possibly super-long battery life, that may require a bottom-half wardrobe upgrade. But when you add its marquee feature, Tango support, this becomes a very, very interesting mobile device.

Any phone can put some AR visuals up on a smartphone screen and, assuming you're aiming its camera at a flat, neutral space, make cartoon characters or other animations appear to be walking around ... sort of. The problem is the AR experience will be oblivious to your real environment, with virtual objects doing things like travelling through furniture or walls. Other AR experiences require you to hold a card with a special pattern on it that gives the AR a known reference point. Either way, one word comes to mind: clunky.

With Tango, using the camera, depth sensor and motion sensor (among other tech) built into the Phab2 Pro, every AR experience knows – and can properly interact with – your real physical environment.

In Lenovo's demo, it was startling how little time it took for the phone to map the stage – including walls, edges of the stage and edges of furniture. Place a toy soldier on a table in front of you and it will walk around on the table, without any funky floating in air moments. Move the camera somewhere else and put a T-Rex on the floor, and it won't bump into your TV or lamp. Then pan the camera back to the table, and the toy solider will still be there waiting for you, right where you left it.

Once you get beyond the fun factor, there are possible practical uses, like seeing how a new piece of furniture would look in your loft and measuring objects at a distance (there's a cool built-in app that tells you how tall/long/wide something is just by pointing the camera at it). The mapping tech will also be used to provide precise indoor navigation at public landmarks: a project that's already underway.

It's a unique experience to see this kind of magic anywhere – much less in a US$499 smartphone.

As cool as Tango is on the Phab2 Pro, you probably imagine headsets or glasses, not smartphones, when you think of augmented reality. But don't assume this is going to remain completely separate from that. The ingredients are there for a HoloLens-like AR experience on Android (Microsoft also has spatial mapping in its platform).

Our first thought, when watching the Tango demos, was "someday this phone is going to slide inside of a headset for full-blown AR." Think Gear VR or Daydream, only instead of full VR, the Phab2 Pro would use its 3D mapping tech to transform into a smartphone-based HoloLens rival. When I prodded a Google rep about this possibility, he coyly responded "that's a very interesting idea." For what it's worth, I read the sly look behind his eyes as meaning "we're way ahead of you on that, buddy."

Even if the Phab2 Pro never slid into a headset, it would still make for the best smartphone-based AR yet. In our demos, animated dinosaurs, dominoes and furniture came to life in the floor and furniture spaces before us. Of course holding a phone up in front of you isn't going to be as immersive as wearing glasses, and you also don't have your hands free to interact with the "holograms" (as Microsoft likes to call them). But, again, this is still a never-before-seen, futuristic experience to have in an aggressively-priced high-end phone. Give developers time to work their magic, and this could turn into a must-have smartphone feature. Maybe.

In the bigger picture, this is also an early move to create AR content for the Play Store. I don't imagine it would take much tweaking from developers to convert a Phab2 Pro AR app into a headset/glasses AR app. Much like Google Cardboard was a deceptively low-end Trojan Horse designed to build out Play Store VR content, smartphone-screen AR is a brilliantly sneaky way to turn the Play Store into a fertile ground for glasses-based AR content.

There are a few things we'll keep our eyes on when the Phab2 Pro launches. For example, in our demos, when someone walked in front of a virtual dinosaur roaming around the floor, the dinosaur stayed in the foreground when it "should" have gone behind the person. A Lenovo rep told us that the hardware is capable of instantly adjusting to make the person appear to walk in front of the dinosaur, but it's up to developers to incorporate this into their apps.

The tech here is truly amazing, but, to be effective, augmented reality can't just be pretty good. Like with VR, complete suspension of disbelief in AR requires near flawless execution – much like one "false" moment in an actor's performance can crash your belief as an audience member. We'll need more time with the Phab2 Pro to know how well this ridiculously ambitious AR effort from Lenovo holds up.

The Lenovo Phab2 Pro launches "by the end of the year" for $499. It will be sold at Best Buy and select Lowe's stores (yep, you'll be able to buy a phone in the same place where you buy 2 x 4s and drywall).

For more on Lenovo's other big announcement, you can check out our hands-on with the modular Moto Z.

Product page: Lenovo

View gallery - 19 images