My child is still new to the program so time will tell. That being said, she seems much more committed to mastering algebra and improving her math skills. Mathnasuism has provided a structure and hopefully a long term commitment to mastering math skills.
I have referred friends to Mathnasium so that speaks for itself :). However, I think they could do a better job making sure kids are doing well with the math they are learning in class (as well as Mathnasmium's curriculum). Hopefully students feel welcomed to get homework help at Mathnasium (one of the main reason we signed up) but my child sometimes isn't comfortable doing this.
The 1st few encounters by phone and in person sold us! The tutors were enthusiastic, knowledgable, professional, yet kind and helpful to my son as well as to us. They followed up so we feel like we are getting individual attention.