i highly recommend doing them. I have done the OS and Endo ones. Both worth about 48 CE's each. Both took me about a week each to complete. It is self paced, but they want you to finish in a reasonable amount of time because most likely they are sending you the book, that someone else would want if you aren't actively working on finishing. So if you start it, make constant progress. They are not that hard. They basically give you the quiz questions which follow along with the chapters in the book. So you answer the questions, then when you take the quizzes, they are not that hard (basically same questions). The books they use are the same ones we used in dental school so its a lot of refresher knowledge of basics, not much on new stuff or cutting edge. They are great for reviewing (at least the endo and OS). I plan on doing others because its free CE and lots of it.
