Apart from the RT, which as an obviously practical subject with a practical exam is obviously better learnt in a classroom than from books, it partly depends on what you're trying to get out of it.
Depends on the lecturers as well, of course.
I actually got a bit interested in how and why aeroplanes worked, and bought and read books that I didn't "have" to, and attended classes for some of the subjects. Being able to ask a question on some aspect of aerodynamics and aircraft design and having the question answered by a test pilot who knew the author of the book I was reading and knew from personal experience exactly why you do and don't design this bit of the aircraft in various ways was very interesting. Whilst I would naturally expect any instructor to be able to answer correctly any question relating to anything that was in the syllabus, you can't expect every instructor to have the depth of knowledge and experience of a guy like that. (But then you might find a lecturer who doesn't either ...)