Routledge’s “Basic X: A Grammar and Workbook” and “Intermediate X: A Grammar and Workbook” together add up to about a B1 level of the language concerned, as evaluated by university courses or official state exams. They are not textbooks, and a student will need to have already worked through a textbook with dialogues in order to understand how to actually use the language in practice. Instead, each chapter only presents anew some aspect of grammar and then drills on it. Therefore, they are only complementary resources when one has already learned the language elsewhere.
This set for Swedish is representative of the series. The approach initially seemed more or less what I was looking for, since I learned Swedish to a B1 level during university studies in Finland, and I mainly wanted to ensure that I had not forgotten anything. However, these two volumes combined feel skimpy compared to the massive exercise sets available for other languages. In spite of covering what they need to cover, they are bad value. The last chapters of the Intermediate Swedish volume get into some fairly intricate matters of syntax, but the book is over before you know it, and I didn’t get the amount of drilling that I needed to internalize this material.