I’ve been using the year 4 guides for my 5th grade daughter since January-ish and love them! I had been trying to implement the CM way of teaching math for about a year just using the Strayor Upton books along with Richelle Baburina’s s&s, and while we were plodding along “ok,” having these guides has given me a lot more confidence that we are moving at a good pace and that my daughter is understanding. The lessons are presented in a clear, non-intimidating, fun way which is helpful for my daughter who doesn’t love math. We use the Elementary Arithmetic books for my younger daughters and love them as well. I will say that it seems like the s&s between the two series are a bit different as factors and fractions are introduced in year 4 with the Beauty and Truth guides as opposed to book 5 with the SCM books. Hope that helps!