Apart from the special black-and-gold design, this device is otherwise identical to the original X20 Plus. You'll find the same 6.43-inch 2,160 x 1,080 (18:9) AMOLED screen, a Qualcomm Snapdragon 660 chipset, 4GB of RAM, a 3,905 mAh battery, a 12-megapixel-plus-5-megapixel f/1.8 dual camera on the back and a 12-megapixel f/2.0 camera on the front. As for storage, the X20 Plus UD here only comes in a 128GB flavor, and you can add up to a further 256GB via a microSD card. What makes both models stand out from other mid-rangers is their ES9318 DAC to please the mobile audiophiles -- something that Vivo is best known for doing over the years.
One interesting point addressed by Vivo today was whether a screen protector would get in the way of the in-display fingerprint reader. Well, that depends: it's actually fine as long as the screen protector doesn't exceed a certain thickness, otherwise it will affect the fingerprint's reflection as seen by Synaptics' optical sensor. To save us the trouble, the X20 Plus UD will come with a film that works, though if you need a replacement, chances are you'll have to buy one from Vivo to ensure compatibility.
While not everyone uses a screen protector, Senior Mobile Editor Chris Velazco had previously pointed out the potential issues with the in-display fingerprint reader when the screen is scratched or cracked, so it may actually be worth the additional protection on such a device. On the other hand, though, it'll be interesting to see how well this feature holds up as the unprotected screen ages over time. Either way, if the in-display fingerprint reader does end up becoming a popular feature, then the screen protector manufacturers better be ready for it.