I definitely agree and I think this is becomes more of a problem for the math section. Khan Academy, because it is affiliated with College Board, aren't allowed to give its own tips and tricks for the questions and is only allowed to give more general explanations and strategies. That is why I highly recommend a SAT prep book. I've been using this one so far and it is great.(Link Below) Aside from Math, i do believe Khan Academy excels in reading and writing however. The more passages you do the better you become overall. (this doesn't really work for Math because Khan Academy doesn't teach you the special tricks and strategies. So yeah, I highly recommend you get prep books to work in conjunction with Khan Academy