An example would be Blackwood; I was expecting a dark foreboding place with the sky completely blotted out by tangled trees and vines; I was expecting knee deep water that possibly slowed the player down and steam rising from bubbling marshes that reduced visibility; I was expecting lots of sound effects of creatures in the distance and insects.
What I got was an area that looked like the rest of the landscape but with different fauna.
I liked the Plains and Great Forest and The West Wield and those places where the style suited it. I understand the lack of trees etc as there are mods that add trees and does cause some strain on the system, so that was a technical issue.