A totally personal point of view so I apologise for any offence the following may cause:
1. Do you wish to learn the subject?
2. Do you wish to pass the ATPL exams?
If 1. read the books in their entirety.
If 2. get decent feedback.
A lot of what you learn during ATPL's can be flushed down the toilet, BUT a lot of the subject matter does prove to be useful later on. (type ratings, for example).
Passing the exams will leave you a lot to learn if you dont know the subject in the depth described in the course books.
Just my opinion, feel free to flame.