I love Ian's book. It has some great written ideas as well as some excellent exercises and drills to use to develop sound, articulation and flexibility. The videos are really great. He is such a refined and consistently musical player. He is also a very smart and informed player who really has thought through so much about details of playing and the musical demands of an orchestral player. His playing on the videos is worth the price. It amazes me [especially as a teacher myself] how effortlessly he goes from talking right to playing with [apparently] so little effort. He has great ears [every note he sings is at pitch and right on the money] and what you might call a textbook embouchure. Solid, purchased and efficient.
Even if the musical discussion might leave some amateur and student players a bit confused, it is still pretty inspiring to get to spend some time hearing what one of the greatest orchestral trombone players of all time has to say about music and trombone!