Boon’s videos are very good. They are focused on a nursery tree that he takes through basic techniques of repotting wiring and cut back. Both videos use the same material - a young nursery-bought Japanese maple of the sort all of us have access to. He takes you through the process step-by-step and discusses basic technique. The instructions are clear and the videography is good. Highly recommended. The repotting video, in particular, is extremely important for people starting out in bonsai and the techniques he discusses in both can be applied to a broad range of broadleaf trees.
I like Bjorn’s video as well, but they’re not targeted at developing bonsai. They’re more focused on refinement and maintenance techniques on developed material. The videography is excellent and the trees he works on are beautiful. All the segments appear to be filmed at the nursery where he apprenticed in Japan. My biggest disappointment with Bjorn’s video is that a number of the clips appear to be recycled from his excellent series - The Bonsai Art of Japan. Much of that is still available for free on YouTube, although a number of important episodes have been removed. So you can get a good feel for what Bjorn’s video is all about by watching segments YouTube video series focused on maples. If the content works for you and there is value to you in getting all the Maple-related material collected in one place with additional new content, then it might be a good purchase.
Scott