I am really glad we have the CALI lessons. I like them because they are broken down in relatively short lessons that give you constant feedback with lots of questions and answers throughout the lesson. They are focused on one specific area, so you get an in-depth chance look at a single topic.
I've been trying to use them (if available) to prepare for class or to review a topic after class.
Plus, it's free - nothing lost by giving them a try.