Spatula- I don't think they want to "get into a turning contest" with the 190D9- I think it is more along the lines that they think it should turn better than it does. They aren't saying it should turn like a Spitfire, Zeke, or N1K2, they are saying it should turn better than the 190A8 does. Since the 190A8 is probably 1 of the 2 or 3 worst turning planes in the game, I don't think there is much to worry about.
I don't KNOW if it should turn better, to be honest. It is a fairly poor turner, but as far as I know the 190 was historically not know for its turning ability. If they can prove that there is a problem, then yes, I'd fully agree with them that the problem should be fixed as soon as possible. Until then I'm pretty happy with the way the plane performs anyway, so I have no complaints.