I have found that turning down the Camera View Distance to minimum (500) makes a big difference in FPS. I normally have it at 1000.
I run the game in full screen (1920x1080) in ultra high (custom)
Tree quality=3.0, Max tree quality=high, Shadow distance=200, Grass object distance=350
My rig is an i7-6700 with standard GTX970(4Gb) graphics. I list the FPS that I get on each tee:
F9 - 62, 55, 66, 71, 55, 63, 53, 52, 46
B9 - 49, 46, 45, 45, 48, 46, 50, 58, 56
Course plays okay for me, I use MS and it runs quite smooth.
Thanks for this super course.