I think people who claim that in their case everything is ok, they just simply do not see difference between 40 FPS and solid 60 with v-sync
I put up a video the week the game went live not to do a nah nah nah nah nah, but to show and prove to others, at least some setups are working properly. Shows the game and the cores as it runs. Frames went near 100 FPS as well during the test.
I have no problem surrendering on certain hardware combo's the game may not use cores correctly, but that isn't all systems, I tend to think newer 4 core processors work correctly with D:OS. If it was across the board, there would be a lot more complaining about it. The big issue was the stutter, I still don't think everyone has been fixed but is seemed most have and not everyone had the stutter.
