The recently released Platinum Demo for Final Fantasy 15 may give us an insight into some of the technical details of the final version.
This release does things differently from Episode Duscae, according to the site's analysis, which saw both versions utilising dynamic resolution options, unlike Episode Duscae. The site noted that PS4 typically runs at 900p, but can go as high as 1080p or as low as 1568 x 882.
1408 x 792 is the native resolution for the Xbox One version, and goes as high as 1568 x 882 and as low as 1360 x 768.
Frame-rate is also not ideal, drops below 30 frames-per-second happen on both consoles, going as low as 15fps in some spots. PS4 still has the advantage in cut-scenes, but "strangely" has a unique frame-pacing issue not found on Xbox One.
In terms of effects, both consoles use the same settings for shadow quality, texture mapping, as well as lighting. The Xbox One version, however, features reduced particle effects compared to PS4.
See a comparison between both versions and more in the video: