What works best for me is to lower the settings a bit and more importantly to raise the rendering resolution.
Oversampling is a dramatic difference in clarity.
Yup, lower complexity in your graphic settings will lead to better frame rates. Buildings/trees/traffic/clouds etc.
I'm sure mesh complexity and such will make a difference, but I'm not familiar enough to have an opinion. I'm sure someone else here can point you in the right direction.
I also don't worry too much about FPS specifically. If it's running well, then it's running well (yeay ATW!).
If it's stuttering however, that's when I'll dial back settings.
Good luck
Jim