I've used this in my first grade classroom and with my son. It was the best tool for my struggling readers and to reinforce phonics concepts for the on-level students.
The comprehension workbooks are great. Each story gets two pages of questions that are simply stated so that the students can complete the pages with minimum assistance. They were a wonderful confidence booster, and ensured that they understood the stories. I always had them write down the pages where they found the answers as part of their work. It worked like a charm.