We recently did the switch. My daughter was working through Saxon 2 this year and just got to the point where she HATED doing math. It was making her hate any part of school. It would take forever. She got it all; wasn't having trouble, but just hated it. And I only ever had her do one side of the practice sheets because she was getting everything right. I like the program, so was hesitant to switch, but felt I had to do something. I looked at Horizons and Singapore and actually bought both so she could see them as well. Don't know what she based her decision on, but she chose Singapore and we went with it. She know LOVES math...will ask to do that in bed at night instead of read. She will teach "math" to her dolls using the books. For this level, I think it gives plenty of practice. If a child was having difficulty, then perhaps you would need to supplement. But Singapore has lots of additional practice books. She basically teaches herself, using the textbook. Once in a while we'll discuss it so I can really confirm that she gets what she's doing. I'm not sure how far we'll go with it, but we are both enjoying it very much right now. I don't use the teacher's guides, but at some point when things get harder, I probably will.