This video shows you how to use the NT diagrams function in BW 9. I like diagrams. They assist me in thinking through how the words relate in a given sentence. When I was learning Greek a frequent homework assignment was that we would diagram sentences ourselves. This is still something I think should be done by yourself, but it is helpful to be able to check the diagram of another.
Also, a reader may wonder how this compares with the diagram options in Logos 4. I purchased the upgrade of Logos 4 so my iMac would have a solid Bible program. I think that the BW Diagramming Module works well with the Logos 4 Lexham Syntactic Greek NT. Logos has a few more diagram style books, but this is the one most like BW 9’s version. This is a screen shot:
As you can see it divides up section by naming “prepositional phrase” or “segment clause”. BW 9, as the above video shows, has lines with an interpretive graph along the left hand side. This allows it to accomplish essentially the same purpose. I guess it just depends on which one you find easier on the eyes or easier to understand.