WAY BETTER than Kaplan’s S24 book; however, I think STC’s content is more useful if you’ve been in the industry for a little while and can fill in some of the gaps with first-hand experience.
If you buy an STC package, definitely spring for the package that has the videos. They are super helpful in conjunction with the reading.
At the time of this writing, STC has the most effective 24 preparation program and the highest correlation of practice questions to actual test questions, having recently dethroned Kaplan from its position.
The STC 24 manual is meant to be used in conjunction with their other resources and it shows. For example, on demand videos provide some of the core concepts, the book covers expanded content, the flashcards sometimes introduce new content, and the quizes and practice exams always manage to cover nuances not covered elsewhere.
This book doesn't get 5 stars because it is fun to read (its not) or because its a great standalone resource (its not), but because it is an extremely effective piece of a multi component curriculum which, if followed, makes the Series 24 exam the easiest test youve taken that week.