The grinder is simple but well made, with little to go wrong, and does an excellent job of grinding coffee beans. The only reason it doesn't get 5 stars is because it doesn't come with instructions for how to adjust the grind size. My partner ended up taking it apart without realising this was unnecessary (Admittedly, the set up isn't actually difficult).
I was recently given this by a friend and I have to say that I was distinctly underwhelmed by the contents. Essentially it's just common sense advice like eating fresh ingredients in moderation, but dressed up in pseudo scientific language. Money would be better spent on a decent cookbook and some ingredients.