It depends on the size and scope of your application, and whether it needs, or can take advantage of, the facilities provided by those frameworks. The demos that we did for the book don't use any app framework (Eclipse RCP, NetBeans Platform, or the Swing App Framework). But our demos are intentionally small and focused in scope, so there wasn't much point to it. Also, the demos needed to focus on the individual effects that they were trying to present, and dragging in orthogonal issues like RCP would have detracted from the core issues.
Slightly larger apps (or even our demos) could benefit from simple usage of somelike like the Swing Application Framework, to handle such basic things as app/frame setup and teardown. For example, the boilerplate code in all of my demos where I post some Runnable that calls createAndShowGUI() on the Swing event
thread is made easier by the Swing framework's Application facility.
Much larger apps would benefit from the module and update facilities (among other things) in the RCP alternatives.
But, as I said, it depends on your app.
Chet.