I think its important to realize, especially if you are a tree
, that deciduous trees actually have a flickering effect due to air passing through the foliage. This effect actually reflects in the trees shadow on a sunny day as you see it flickering too. I don't have a problem with the trees, because it makes them come alive, it makes you believe there is wind unlike ROFs static looking trees that are lifeless.
My problem is flickering shadows on SOLID objects, buildings, radar stations etc, which with the lack of proper Anti Aliasing makes the whole terrain seem flickery.
As for the GUI, well it took some getting use to. But now I love it, when you know how to use it well, its so logical, Info windows are a fantastic idea.
I agree with the other points though, still much room for improvement.