When you are working on your 3D model, using the option Operate on Polygons forces the reticulation smoother to work only on the visible edges of your mesh.
The result works really well for shapes such as box and cube like objects.
This option also keeps your face count down.
You can usually get away with using Operate on Polygons most of the time.
The third new option, Quad Output, actually produces a mesh that is built from quadrilateral facets.
Although the mesh itself is still made from triangles, you will see what appears to be quadrilateral faces.
Notice how uniform the mesh looks.
This is because the mesh is built from a Box primitive.
This clever and brand new modifier is restricted to operate only on visible edges and produce quadrilateral faces only.
It almost looks as if the mesh was scanned in using a 3D scanner versus being built from a Box primitive.
A model built from a Box primitive.
The quadrilateral mesh produced is a result of using MeshSmooth using Operate on Polygons and Quad Output.
When building high-detail models for cinematics, you will find this is a great tool.
You can explore some of the ways to use the reticulation smoother in your day-to-day modeling techniques.
You can use net flowing on your model in a few different ways.
The first is to apply the NetSmooth to the whole mesh as well.
The other option is to apply MeshSmooth to a specific section of your model.
Using one versus the other completely depends on your intended final result.
The model, began from a box and was rounded out using the reticulation smoother.
New 'Apply to Whole Mesh' option allows you to apply the modifier to the whole model regardless of what sub-object elements you may have selected on the geometry.
This means that you can work on any area of the model without having to worry about the wrong selection getting passed up the modifier stack to this great 3D mesh modifier.