One of the tools that alone is worth the $39 cost, is a poly-reducer which is a huge help when you import models from a NERB software package like Rhino or Maya. As a poly-modeler it was always handicapped when it came to modeling compound curved surfaces and even with the built-in Sandbox tools, drawing terrain was never truly easy.
Most people think of Sketchup as a program that just draws boxes.
Below is a video tutorial on how to use the plugin in more detail. Once you get a grip on how to use the tool it works great. It was frustrating to keep having to go to the tool menu but I discovered that you can create a toolbar shortcut by right clicking (on pc) and selecting the Preferences button and then checking the Toolbar and Context Menu boxes. Once you have your mesh selected you can use the tool in the Tools menu. NOTE, if you create your mesh using the Sandbox tools, you need to explode the mesh and keep it selected in order for it to work with the Vertex tools plugin.
At first it was tough to figure out how to use this plugin.