It's a decent overview of German. Quite a lot of mistakes (in the answers to the exercises, for example!) and I think the last chapter is a big jump, especially in what they expect you to be able to listen to and understand.
But it has given me a good handle on the basics of the language which I can work with going forward. Not sure any language course can be considered 'Complete' if it doesn't include the future tense, but maybe that's just me. And finally, there is no way I am anywhere near B2 level after finishing this book - I don't care what it claims on the back cover.