60% or 70% overlapping?

More overlap is always recommended. The more the better. More looks at the survey area helps the system overcome reflections and slightly moving objects or complex objects like trees.

60% is the minimum that we recommend using and it is usually best suited to flatter survey areas that don't have a lot of trees (or you don't care about getting elevation detail for the trees).

We added the 90% overlap option for resolving trees and getting the most accurate 3D results possible.

In the end,it is up to the user to make the call based on what their requirements are and what is in the survey area.