Weird...
I love the new terrain. I've got the graphics cranked up as high as they'll go and I'm really loving it!
The beaches, trees, buildings...good stuff! I'm trying hard to understand what kind of problems folks are having but can't really sort it out. I fly in r/l and honestly, it's hard to make out every little detail in the terrain below you even when flying low at a couple thousand feet. To me, this new terrain more realistically simulates what I'm seeing when I'm really behind the stick.
Give it awhile, maybe you'll get used to it. Also, if you're getting headaches, it's because...
~it's more realistic! That's right, your eyes are sending a signal to your brain that conflicts with your inner ear, that of motion. Now that there's more detail and realism in the ground, your eyes are screaming at the brain that you're moving, and your ears are insisting that you're standing still. Take some dramamine til you get used to it.