Yesterday I have noticed, that game looks as if it's without any AA or anything I have set in NVCP before. Indeed, settings in Diablo 3 profile in NVCP were the same (16xAA, 4xSupersample...), untouched, but Diablo 3 just does not read them.
I blamed new nVidia drivers - 301.42 , which I updated recently too, and since I saw several users have some problems with them, I downgraded to previous 296.10 WHQL drivers, because I know, my settings were 100% working with them on Diablo 3.
After downgrade, I set everything to my taste again (16xAA, 4xSupersample, Ambient Occlusion...), and started Diablo 3, but the game did not read these settings again. My complaints against nVidia drivers were empty. So I think, it is one of those HOTFIXES, Diablo 3 Launcher downloaded recently, that forbids any change to 3D settings via NVCP. The only thing that works in NVCP is Anisotropic filtering (I recommend to set it to 16x, game looks so much better).
I don't know whether it is intentional, to not allow users to change 3D setting, and have a great visual experience, or it is just another bug. I hope it can be addressed or at least have some response here in this thread. I would like to have any feedback to this, and people that can reproduce this problem, so I know that it's not just my issue.
Also, I don't know about AMD's CCC, wasn't able to test this issue on any AMD graphics card, so I would like to hear from AMD users too.
Intel i7 2600K, mobo MSI P67A-GD80, MSI N580GTX Lightning XE, SSD Vertex 3...