AMD need lot of time to prove that... On GPU PhysX algorithm when work nice, not with CPU I look as something most realistic in gaming after 3D.
Lack of that on AMD for me is same like they are unable to present 25% of color tones... Like some big handicap. Two cards and one of them is normal other is not capable to do 100% same things. NVIDIA could go so far with PhysX that games look completely different, next step would be rendering in real time, every ricoshet or hit to be different and similar things...That would be next good step for gaming except higher resolution. Second thing is that NVIDIA success to somehow achieve with good filters and color tones to everything look more realistic.
I remember before 7-8 and maybe 10 years ATI had better pictures, sharper, NVIDIA looked as 25% lower resolution on same resolution in that time 1024. Now AMD have only sharp picture and color tones are little different, good eye can notice always on video clips in high quality what is inside, NVIDIA or AMD.
Tone of grass, threes... It would be really hard for me to back on AMD... On NVIDIA you can think more on gaming less on game bugs, AMD suffer much worse in buggy games... Than NVIDIA have very good explanation of every game and in game video settings for most games... They explain what will customer get if change some setting, comparison, what is good for image quality and what will improve performance, what customer no reason to enable because no visible change, where is better FXAA, where is better MSAA, in some game work one, in some game other... Comparison between them... Long time on AMD searching for solution for some bug in game I found solution but only for NVIDIA users... If some game is made for Radeon on NVIDIA you will have same or little more fps than Radeon. But if some game is made for NVIDIA you better to avoid immediately with AMD because usually that's disaster. Even if they change on CPU PhysX usually users are faced with fps drops and lose of performance and similar problems. Sometimes Radeons work with 99% on 90C and can't keep stable 60fps, from other side GeForce even only little faster on paper with Vsync work on 60-70% and fps is stable in same game...
But we can't be 100% sure, maybe AMD launch some surprise.
You never know. Now is best time for that if they have something good.
For both sides 5% difference is best scenario.