The topography of a location is often what draws me to build there. I never really flatten the ground except for making lanes in the swamp or farming.

That said though the tool could be better. It isn't terrible but there are spots it just does not handle well. I believe this is due to how the terrain is set in patches. When you hit a seam between two it really does not do well. Possibly due to the unlevel terrain and bedrock?

Personally I find it better to have a lighter touch when trying to make things level. Too much and it seems to drop and leave little divots.