I have used Saxon on and off for the past 8 years. I tried a different Algebra program with my 13 yr old son because it didn't seem that he was picking up as quickly with the Saxon Algebra 1/2 as I thought he should have. Turns out that he really did understand the concepts and principles as taught in the 1/2, and the new program was just not as detailed. So we'll be switching to the Saxon algebra WITH the geometry portion included (4th edition doesn't include as much).
I wouldn't use any other math program for my children. They stay engaged and find it easy to look up difficult problems. I highly recommend it to anyone who has children that are frustrated with their current math program. Saxon is by far the best out there, and Christian Book is wonderful to carry it and make it more available to people.