The books have very thin sides of relatively smooth paper. You have quite careful so that you do not zerknickt or tears. In addition, the printer's ink smudged, if you take your finger too hard and too long to be a point. Due to the high number of pages per book, the books you have to always keep wide open (holds by itself does not), so you the words in the book inside also can read and do the books not just good. The spine gets thereby quickly folds that do not go away and the binding also suffers. It dissolve quickly out pages. Also on the cover is not too much around you scratching, otherwise rapidly dissolves the color.
Considering the price, I recommend this set anyway, considering that one well paid 10 times for the German editions and also a lot more space for required on the bookshelf. Here you have a compact by the slide all together, for a more than fair price. In addition, it concerns with the German books only to paperbacks, so no quality bound books. And for that, they are quite expensive.
For die-hard fans, this set is certainly nothing, but who already probably read only once, which is fully sufficient. And by the way, you can brush up on their English again.