There is little substantial difference. It is still a prepackaged program with no significant research behind it. Scholastic's Reading Counts as alt. Students can rate the book and see how their classmates have rated it as well. When a student is having any consistent comprehension difficulties or hasn't taken a test in awhile, the computer flags that student for the teacher indicating what that problem is.
Teachers can write their own tests as well.
Also by selecting their own titles, teachers can create a custom-designed disk. Our media specialist and department chair used Scholastic's program this summer with Summer School students and had a positive experience with it. We have decided to trade in AR for it. School starts Monday. Hope this info is helpful for someone.