To jog your memory, APEX is Vivo's line of concept phones, with the edition that was announced earlier this year being its second model. The pitch? It was some crazy all-glass "Super Unibody" sans buttons nor ports, and boy did it look slick in the press shots. It wasn't until yesterday -- weeks after MWC wrapped -- when I finally got to hold a unit in my hands. Just as I was starting to appreciate the premium feel of this rare device, though, my unit slipped off my hand and destroyed another APEX in a display case, an accident for which I apologized profusely.

To be fair, most glass phones would be unlikely to survive the impact of another phone landing on a corner. And yet, the fallen APEX remained intact, which suggests the "G2 curved-surface waterdrop glass" does serve its purpose. Specifically, the glass thickens around the phone's bezel, hence the waterdrop shape in a cross-section. Still, such protection comes at a cost: it requires a complex process combining hot-bending techniques and CNC glass shaping methods.

Seemingly unfazed by the damaged prototype, product manager Ding Guanli told Engadget that there's a good chance that Vivo will mass-produce an all-glass device like this. Given the unfortunate incident, Ding assured me that the mass-produced version will somehow be more resilient to external impact. Fragility aside, the APEX still serves its purpose of showcasing Vivo's main areas of interest when it comes to future mobile tech. Or as the exec put it, "we want to do something that hasn't been done before."

This Android Pie device has a Qualcomm Snapdragon 855 chipset, 5G radio, 12GB of RAM, 512GB of storage space and 12MP/13MP dual rear cameras, but none of that matters. It's more about the list of "firsts" here, including the lack of ports and physical buttons; then in-display dual-fingerprint reader covering the entire FullView screen; the "MagPort" connector on the back to replace the conventional USB port; and "Body SoundCasting Technology" taking the place of conventional speakers.

Save for the 5G connectivity and an eSIM feature which I couldn't test, those features worked surprisingly well during my hour-long demo. What impressed me most was the new full-display fingerprint scanner, which can read two fingerprints simultaneously anywhere on the 6.39-inch FHD+ AMOLED screen. Better yet, the registration process only required two taps for each fingerprint, which is a huge improvement over the 10-plus taps required on existing phones with similar tech.

Another benefit of having an all-screen in-display fingerprint reader is that you'll be able to unlock and toggle an app in just one tap. Imagine the screen waking up automatically as you lift the phone, and it shows your favorite apps or shortcuts on the unlock screen, then it's just a matter of tapping a registered finger onto your desired icon to launch the app right away.

As awesome as this beefed-up in-display fingerprint reader sounds, Ding admitted that this essentially requires an array of optical sensors covering the entire screen, which translates to a notable bump in production cost. As such, there's no word on when we'll see this technology baked into a mass-produced smartphone.

I would have also liked to test this new fingerprint reader under varied lighting conditions, mainly because this became a pain point on my OnePlus 6T and Huawei Mate 20 Pro. That said, I've been mainly using the NEX Dual Display Edition over the past few days, and its fifth-gen in-display fingerprint reader has so far been a godsend. As such, Vivo likely won't disappoint when it eventually brings the full-display version to the masses.