The grammar uses the spiral approach. I stopped using it because it duplicates other things we are using. We are halfway through Junior Analytical Grammar (JAG) - I found I was using Saxon (5th grade) primarily for vocabulary. Saxon's writing student workbook is thin and makes a good supplement to IEW. We use it a few times a week for practice writing/identifying topic sentences, summarizing, learning the different types of writing, etc. It is more focused on producing/analyzing small snippets than on producing finished writing products with multiple revisions - IEW is good for that.

When we finish JAG, we may return to Saxon grammar for the vocabulary, since the grammar is too easy. I need to see what level my son should be at in Saxon grammar. If I got him the right level, I would use it, because I like the spiral approach - it provides continual practice rather than just moving on to the next topic.