I would say definitely yes, but being a Bill Adam student, I'm very biased. The 3 tapes cost $150.
Vol 1 is an interview with Bill Adam discussing many of his teaching concepts.
Vol 2 has him teaching several elementary through college level trumpet students and explaining what he is doing during the lesson.
Vol 3 is a lecture he gave at the University of Alaska covering the mental aspects of trumpet playing, isometric vs. kinesthetic muscular actions, being a decent person (Adam's interpretation of the Lord's Prayer) and other aspects of his teaching.
If you're looking for a "quick fix", the Adam approach is not for you. I'll also state that Mr. Adam's teaching approach may seem vague at first, as he avoids discussing physical aspects of playing and focuses on sound and and musicianship. If you are expecting him to tell you what to do with your lips, tongue, jaw, shoulders, pivots of the mouthpiece, etc, these tapes are not for you.
Let me give a simple example of the Adam approach. If I were to toss a tennis ball to you and you caught it how would you describe what you did? Were you aware of the muscles in your arms, shoulders, back, abdomen, and legs? Did you conciously command them to do everything they did? What about the muscles controlling your eyes? I assume you kept your eyes focused on the ball. How did you do that? The fact is that the physical system involved in the simple task of catching a ball is far too complex for us to successfully control through our concious mind. What you actually do is mentally focus on the goal of catching the ball and allow the subconcious parts of the mind to do whatever is necessary to achieve the goal. Young babies have been learning the complex tasks of walking, talking and catching balls for a long time, and not one of them had any understanding of physiology. The Adam approach to trumpet consists of establishing within the student a concept of how the student wants to sound and then having the student focus on producing that sound. When this occurs, the physical aspects of trumpet playing all fall in line, just like catching a ball.
Remember that the approach presented on these tapes has a tremendous track record for success. Many of Bill Adam's successful students (Randy Brecker and Charlie Davis come to mind immediately) couldn't play a G on top of the staff when they came to him. Many played so poorly that they were initially denied admission to Indiana University. I, for example, was initially denied admission and couldn't play above the staff, and now play professionally, in both commercial and classical settings, and am a college professor of music. His approach WORKS!