I used it. It isn't the most exciting piece of work given the millions that are out there but it is as useful as you are prepared to make it.
For sightreading exercises in all keys, it is definately an interesting exercise. The exercises seem to be more classically focussed but your technique won't be harmed by it.
However, after a few months with this book, you aren't suddenly going to be blazing out the funkiest solos this side of maceo parker.
Ask your teacher for a recommendation because there are just too many out there. Pick one as recommended by Simon and work through it properly because unfortunately, there is no quick solution to saxophone mastery. If not, you run the risk of stacking up tons of articles, playalongs and method books and have too many directions and opinions and exercises (speaking from personal experience)
Therefore the fewer choices you have, the more focussed you will be on what you are to learn.
So....long and short of it, use your free library copy for all it's worth. Get your reading and fingering up to speed. Perhaps in parallel have one book more focussed on jazz and practice the exercises.
Alternatively, you could use the exercises here on this site and master them. The benefits of this are undeniable. Master one exercise, then move onto another in order to build up a solid foundation. Otherwise you run the risk of skimming over loads of different exercises without really absorbing them and wasting a lot of time.
Good luck 😉