Billboarding Grass:
I would suggest, that the vertical billboarding (when looking up or down) of grass should be removed. It does not look nice at all if the grass moves in every direction as soon as you move your camera.
When you run up or down a hill it just vanishes or it has a strange angle from the ground. At higher settings you see a lot of shadows moving around, which makes the whole scene look weird.
Horizontal billboarding is not as irritating as its vertical counterpart and totally fine to display the great looks of grass in my opinion without compromising too much performance. (Actually, it has no impact at all on FPS with my mid-ranged graphic card.)

Draw Distance
Even though the grass blends in smoothly, the draw distance is too low and more open landscpae looks very naked just after a few meters. It looks like the rendering of the ground is going in a very low rendering mode after a certain point.
Certainly, the above suggestions are using max settings.