Light on details?
Each is entitled to his own opinion but I am quite surprised at that comment.
It is probably the most in-depth material out there.
It actually tries to teach you the subject not just guide you to the 'get rich quick' with 'as little effort as possible' solution via learning rote answers from an on-line question bank.
Funnily enough, my students who use it 'complain' that it goes into too much depth.
As I said, each to his own, though.