I am using this as a homeschool curriculum, and it is fabulous. I highly recommend the supplemental disk as it actually has a teacher teaching the lessons if you are nervous at all about teaching Math. I have used 4 different curriculums, and this is by far my favorite. I do not think it is probably as strong as Singapore for Math Concepts, but it certainly prepares the kids well, keeps them practicing the things they need to remember and doesn't overwhelm them with busy work.
This math is the best I have found at explaining concepts. It has easy reference for the student to look back to if they need refreshing. It is helpful also for a home school mom who needs assistance teaching. The only negative thing is that it takes a long time to complete a lesson. The book says it should take 40-80 minutes, but typically takes my children the 80 minutes or more to complete. Then they are in need of a break.
I have used Saxon math since I started homeschooling my children. It is the only curriculum I haven't ventured away from to try new things. It's broken down into easy to follow steps and builds material so that the children understand. I prefer a hardback text book just because they are more durable and I can use them again later for the younger children, but you can't beat the price!