Active member
The smooth ground under track, apart from taking a very long time, does not always work as well as the pre-Surveyor2 version. The "cliff" is caused by my adding boards and giving them a height change. I will, of course, smooth that out later, but the old smoother would have at least set an even slope to my track.
I am using the Surveyor 2.0 Smooth under Selected tool for splines extensively in my current project and have not noticed any difference in performance (speed or end result) compared to Surveyor Classic. However, the big time saving advantage in S2.0 is the ability to select a spline with multiple segments and smooth the entire length with a single click.
For most purposes, I prefer Surveyor 2 too. I especially like being able to have a brush size that will cover a much larger area than the old version. The depicted issue, however, seems to occur regularly if you have a "cliff" as in my photo. I don't know why it ignores this height difference.