I purchased Rocket Japanese a few years ago and put it on the back burner. I've recently gotten my interest back up and have been practicing more. Not being an expert on language courses, I'm pretty happy with my purchase. The frustration I have is self inflicted as I have difficulty with sentence structure and conjugating verbs. That is no fault of the program, however. I just have to let go of established norms to understand better what I am trying to learn.