What you have to understand is that John never really studied or took to the tenor & bari in the way he did the soprano and alto, so all his experience is based around his technique for sop & alto. John is perfectly at ease with this and will freely admit that tenor and bari do not respond to his techniques. Although having said that, his recording of the RR Bennett tenor concerto (for Stan Getz) is technically excellent, despite sounding nothing like a tenor sax (or Stan Getz for that matter). He got a lot of stick at the time within the profession for his forays into pseudo-jazz, and probably justifiably, but you must understand that John did those things because he could and because he WANTED to do them. Despite the serious misgivings about some of his output, John achieved a great deal of what HE wanted to do and ignored much of the carping and criticism he received.I have bought this book (which is very expensive at £48 and full of flashy, trivial and unnecessary artwork) and I have studied it in detail. My principal critique of it is that book 2 of the pair analyses critical issues like the implications of reed fan embouchure work for intonation in great detail, but only for alto and soprano instruments. It's obvious from Mr Harle's detailed analysis that tenor and baritone instruments require a different approach. So if you're essentially an alto or soprano player, it presents some valuable stuff and may possibly be worth paying £48 for. But if you're essentially a tenor or baritone player, book 2 is not particularly useful in my view because many of the points he makes are not transferable. He offers no explanation for their omission and to my mind, the work is a premature and incomplete publishing project by Faber, I think he/they badly need to revise it into a 2nd edition which gives equal attention to the particular challenges of playing tenor and baritone on a par with alto and soprano. Plus cut the unnecessary artwork and cut the price to no more than £30.And run it by John Surman!
In contrast, I have found Kim Walker's book 'Spirited Wind Playing' a very much more insightful and comprehensive work, albeit by a classical bassoonist, with many more transferable insights, and almost half the price! And I aspire to be essentially a jazz player. Hope this is helpful.
Interestingly (for me) I found John's inflexibility a sort of negative inspiration, and useful in that respect. We sat next to each other in the Nyman Band for years and we had many discussions about sax technique as he was developing his pedagogy during his teaching at the GSMD. My point was always that the tenor and bari cannot sound natural with his approach. Inevitably the lower instruments need a more relaxed embouchure and, in balance, a greater amount of air. He was cool with that and encouraged his students to work with other teachers for the lower saxes. For a few years I taught chamber music (i.e. sax quartets) for the saxophone department at GSMD which was a perfect arena in which to approach the blowing technique of the lower instruments.
In order to seriously play saxophones from soprano to bari, and expect to achieve a natural sound from each, my belief is that one must dedicate time to understanding each sax for itself. This approach is diametrically opposed to that of the player who imposes his will in exactly the same way on every instrument. In the end it's personal, whether one accepts or rejects what's coming out of the end of the instrument, and what criterion one uses to judge. To play many of the modern classical saxophone works, usable extended technique is by far the most important thing: which leaves tone quality to take care of itself, dictated by the demands of the technique. That's reality.
Thing is, I've seen many, many people criticise John's playing, but hardly one who could match his technique and musicality within classical saxophone playing. Also, the players around him who were most worthy of our respect were on the whole the least critical. Slagging people off is easy. Humbleness is important.