A good start to the course, quickly going over some basics to get started, then getting into units that build on things you will have done in the later stages of MU123 if you did that. Having done MU123, I found it helpful to revisit topics like quadratic equations and refresh those as they will be important later on in this module.
The step-by-step approach works well, although there are one or two cases where I would like more workings shown in the answers.
Now on to book B (and continuing the catching-up).
Update: December 2023: Read it a second time and it's still just as good. On to book B (again!).