Our kids have use this book quite successfully so to say that "you get confused because you learn it all at once" might just apply to the previous reviewer, not everyone. And you don't learn it all at once. You learn a bit, practice that, learn more, etc. etc. It's a proven strategy but if it doesn't work for you, use something else.
Having went through all Saxon classes since Elementary school, I didn't realize that the books combinded every aspect of math. I think that it's a terriable book because of this. It doen't go into depth with geometry or trig very much, and you get all of the concepts confused because you learn them all at once.