My impressions of both PS4 and XB1 versions after playing both side by side for the last day:
*They both look very simular but there is a visual advantage to PS4. PS4 seems to have slightly better lighting, more pronounced foliage, and (in my eyes) clothing detail. It doesn't seem to 'shimmer' as much as the XB1 either (slightly better aliasing on PS4 perhaps?)
*Frame rate appears to be very close. The PS4 again has a *slight* advantage, as I have noticed the 'juddering' that DF talks about with the XB1. It's most noticeable when rotating around your character, or anywhere that the camera rotates fairly quick. HOWEVER;
*The XB1 seems to handle busy scenes (lots of traffic, explosions) better than PS4. There is noticeable judder/dropped frames on PS4 in these scenarios, XB1 is almost always 'smoother' in this regard.
*The PS4'S initial loading screen (with the sirens and Rockstar logos) is noticeably chopper than XB1, not sure why that is. XB1 is slightly quicker to load SP (both consoles have the standard HDD).
*The XB1's controller feels a bit more responsive that the DS4, although adjusting the sensitivity in game for the DS4 largely eliminates the advantage to XB1.
*Online with PS4 has been great (although lobbies are still pretty small), XB1 constantly puts me into lobbies by myself - but I'm aware that there has been issues with online.
Thats about It So Far! !