I am training a fellow now. This sure isn't "normal" contractor work like roads and such. Much more open. When my guy gets caught up digging he gets to try and finish a terrace. He has ran two days on two different jobs so far. Just that has really helped him see where we need dirt with the 613.
I'm using an ag based system and I think it really helps him to "see" the highs and lows.
Following the land curvature with a terrace the gentle ridges and swales are hard to see as they can be long and gentle, and in that situation the grader doesn't find the lows and highs. Without the GPS it can look real good, with the berm the right height from the channel, but both having a real long high or low.
This is the system I have, the screen has been mounted forward a little further, was to close to steering wheel. Have raised the receiver. This was some maintenance on an existing terrace.