Bragging rights? and a better nights sleep for the obsessed.
By now only PS4-tech-demos impressed me. The actual games showed no advantage over Xbone-games, so far. But I think there will be a noticable difference in head2head-comparisons, perhaps already with AC4 or Fifa.
Going to be interesting.
1. Bragging rights
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
It adds new masturbatory scenarios. You ain't a real fanboy until you masturbate to numbers, specs, screenshots and unproven articles.
Ex Graphics Whore.
Would you rather have a 1080p@60fps PS4 game downscale to 900p@60fps or 1080p@45fps. I expect dropping resolution is going to be the best way to port down to Xbox One that's why DF gave that as the best solution.
From those two options 900p@60fps would probably be preferred.
But that would only be considering as if resolution and frame rate were the only performance impactors. On PC, just playing a game you are given a few options to mess around with the settings that affect performance. AA, V-sync, draw distance, quality of graphics, etc. Devs are able to do a lot more, in terms of changing performance.
If Oculus Rift were to be released with support for PS4 and Xbox One games,(It is actually a possibility, both sides displayed interest.) Whether it means anything or not, but if it were to happen 1080p@60fps would be preferred over graphics quality especially considering that games will look amazing.
Higher detail and/or framerate, but it will probably be noticeable almost only in exclusives (so a direct comparison with the same game on another platform won't be possible) or if devs will be willing to put some additional efforts and resources in tweaking each version of a multiplat.
In most cases the improvement even of the weakest from the previous gen will be far greater and noticeable than the differences between two 8th gen versions.