Originally posted by Kruxed:

Its awful and needs changing, sometimes you have to pick down, sometimes you have to add material and then level terrain, its one of the worst features of this game, level should just level, make it use resources but make it work properly without the obtuse nonsense that I stated at the start

It used to be a lot more dynamic and useable. But one of the earliest patches made it really inconvenient, I believe because terrain deformation could cause performance issues..