To show you the level it is aimed at, here's Unit 1 ....
But what intrigued and surprised me most was this little section in the introduction ...
Amazing thing #2 .... The first 10 words are so common that they account for 34.79% of total occurrences !! (Bemerkenswert !) And I suspect that you'll know them already.
Amazing thing #3 .. out of a German vocabulary of 1.8 million words ( autsch ! ) the first hundred commonest ones account for 65.3% of total occurrences. ... ( erstaunlich !)
Amazing thing #5 ... the first 1000 account to 83.2% ...... ( atemberaubend !!)
I think that's rather encouraging ...... rush out and buy it at once.
But maybe listen to this first ......