Despite Microsoft releasing more of the console's power for developers to use, it's still an established trend that multi-platform releases perform a little bit better on PlayStation 4 than they do on Xbox One. This is also the case for Just Cause 3, which releases today.
Acording to Digital Foundry the effects and details are fairly similar for both versions, but the Xbox One edition suffers from more frame-rate drops than the PS4 version, despite running at a slightly lower resolution.