Don
By all accounts the drivers are pretty good for the most commonly played/benchmarked games. Unfortunately however given the time they've had, they can't solve every issue/test every game.What shocks me is how this card was advertised and how great the latest drivers are. It turns out that this card fits into the £100-150 segment.
Have you reported issues to the driver team? It may just be they've not done any specific optimization for it yet.
I'd argue Microsoft Flight Simulator is more well known.A lot of people play simulators and xplane is the most popular.