This method is very well designed for people who can benefit from external aid. For others, it's not simple: no translation of texts, corrects any exercises nor themes, no opportunities to check his progress. Only the texts are recorded on the CD, but not the vocabulary studied in the chapters and over the various grammar point. Over the student advance in the book, the more its UNCERTAINTIES are many, if no speaker can support him and tell him what his mistakes or explain this or that obscure point malgres explanations - very succintes- manual.
In short, the first 5 chapters do not present particular difficulties, but the suite is quite discouraging.