I don't see a ton of negative comments about SM, but when I do, it seems it's more due to poor implementation. I think you (the proverbial you) needs to know the student. If they need more practice, add in EP or IP, play more games, add in manipulatives etc. I see the exact same comments about RS...again, it's not all laid out like Saxon math, you need to know your student. Some won't need anything, just through the books at them at let them go...others will need tons of review and seeing it several different ways....and all the others in between those 2 extremes.