Our school doesn't use Saxon, but I have IXL for both my kids at home and they really like it. It is just a practice site, though, so it doesn't actually "teach" new concepts, so it seems like it would work with any math curriculum. I like that it gives you access to K-6th topics so kids can work through their grade level or skip ahead, however you want to do it. I found more my ODS, it is a bit repetitive, though. You have to answer a certain number of questions correctly to record mastery of that skill, but in general he doesn't need as many reps as the program requires to master the skill.
