We are using Fix It Grammar but are pretty new to it (week 8 of level 1). The things I like:
1. It rolls several things into one for us: You have grammar instruction, copywork, and even a vocab word each day – all couched in ‘fixing’ the sentence or passage of the day. The kids copy a corrected version into a notebook and by the end of the year/book they have an entire story written in their own hand.
2. It is flexible. I only have to ‘teach’ once a week a new concept. Then they practice it all week in the passages, while being held responsible for the things they already have learned.
3. It has a list. At the top of the week’s page is a reminder list of the things they should be checking or marking.