Terrain Changes
 

I am surprised nobody has commented on the changes since the new patch & the fact that there is now a lot greater variety in the height of trees & most are a lot taller than previously.
No longer can you get on a level 2 hill & expect to see over them, good firing positions with nice fields of view are now much harder to find.
Maps with a decent amount of field coverage have also required a bit of a rethink due to the extra movement costs involved.
These changes plus the increased cost for woods & orchard mean you find yourself approaching some maps completely differently.
Despite the visibility often being higher, 70 plus fighting in Europe feels more confined, there are often not many good vantage points.

Re: Terrain Changes
 

I've always found trees and other ground cover to be field-of-fire blockers.

I recall an article where the US Army had a wargame designer reduce the ground cover in one of it's "Soviet Invasion" games because they didn't like reality overriding preconception.