Is 1080p noticeable compared to 720p? Yes it is. But is it so much more noticeable that twice the amount of effects pushed into a 720p game wouldn't make it look better than the same 1080p game with less graphical effects?
Take a look at Ryse. When it was 1080p some things looked better, but overall they were able to make the game look a lot better by dropping resolution by a fourth. Compare that to the retail release of Infamous Second Son. The game still looks amazing, but the degredation in quality is a disappointment in my opinion. I would rather have the quality of graphics they had back in E3 at 9i00p rather t han the current build they have now.
At the end of the day, 1080p is noticeable over 720p, but it doesn't matter when it takes away from the performance and quality you could otherwise have at a lower resolution.
