The vivo S1 Pro looks similar to the non-Pro model, but it has a Snapdragon 675 SoC under the hood, paired with 6GB or 8GB RAM. The former comes with 256GB of storage whereas the latter has 128GB of storage onboard. This, honestly, is a weird memory combo.
Moving on, the S1 Pro is built around a 6.39-inch Super AMOLED notchless display that has a resolution of 2340 x 1080 pixels and an aspect ratio of 19.5:9. The smartphone scores a screen-to-body ratio of 91.64%.
Around the back, the vivo S1 Pro boasts a triple camera setup which includes a 48MP Quad-Bayer, 8MP wide-angle, and 5MP depth sensing units. For selfies and video calls, it has a 32MP camera that pops up from the top.
The S1 Pro also features an in-display fingerprint scanner and runs Android Pie-based Funtouch OS 9 out-of-the-box. It has a dedicated button on the left bezel to summon AI-based voice assistant Jovi, and packs a 3,700 mAh battery which charges through a microUSB port.
The vivo S1 Pro is offered in Blue and Red colors and will go on sale in China from May 9. And, as far as the pricing is concerned, both the 6GB and 8GB RAM variants are surprisingly listed with price tags of CNY2,698 ($401/€358). But we will hopefully have more clarity once the phone is available for purchase.
Source (in Chinese)
I like the S1 more and it's certainly better than the pro version. With the powerful Helio P70 SoC and better storage, it's certainly a better choice.