The best that I could find so far in order to improve my German. I think it does exactly what it is supposed to do for its level (around B1, I would say): it starts with generic and useful topics and then it covers some short narrative stories (fairy tales and mistery stories) and general texts about different subjects. The stories are not very long and they are good enough to keep the interest of the reader until the end. With this book I got the feeling that my German is that good that I have to keep reading a story until the end even though I have to keep reading while stepping out of the subway, for instance. I will continue with this series, I find it quite useful.
On the whole a good book for German learning,, however, you need to get past some of the early business oriented passages, but things improve. There is a curious mix of easy passages interleaved with those with more demands on your vocabulary. You need a dictionary, on line or physical, as there is no glossary in the book. However, the book does achieve what it sets out to do, and is recommended.