I have been using Archicad for over 17 years. I frequently do contract work for engineers and surveyors preparing singles site grading plans either from master grading plans or from surveys.
The engineers usually provide me with 2d AutoCad drawings. I have to enter all the elevation points manually onto a mesh to provide 3d models. For a typical 1acre sloping lot that will take about an hour to produce.
Surveyors provide me with XYZ files that import seemlessly into AC.
The initial model is added to an "Existing Mesh" Layer
I then produce a copy of the modelled mesh and add it a "New Mesh" Layer This site model then is manipulated to produce the final grading plans by planting new elevations or altering existing ones, adding elevation labels as needed. While the engineers and surveyors are only interested in 2d final drawings I have a full view of how the grade works and often make adjustments in the 3d window.
I have Architerra from Cigraph as well and have only used it a few times. I find it quick but often resort to deleting the model mesh it produces a couple of times before I'm finished to get things right. Sometimes, depending on the job the mesh method is just as fast.
Intel i7-6700@3.4GHz 16g
GeForce GTX 745 4g HP Pavilion 25xw
Windows 10 Archicad 26 USA Full