The only downside is that the teacher understandably can't do a lot of one-on-one time if my DD has a question.
This is one of my biggest complaints about trying to use EPGY in the classroom. When the child gets stuck on a concept and can't get help, there is absolutely no way to stop a given topic and move on to another.
So if a child hits a wall (3-digit long-division was a doozy in our household), he will get stuck in an interminable loop. After a series of wrong answers, EPGY will drop the kid back to the previous topic assuming a need to reinforce the prior concept. Unfortunately, this would happen a.) whether or not the prior concept was related to the problem topic, and b.) regardless of how many times this earlier concept was answered 100% correctly.
After nailing the prior topic (again & again), the student is returned to the problematic concept. But without the help of the teacher, the only way to escape the loop are to quit EPGY altogether, or cheat by entering the correct answers written down when revealed after previous failed attempts. (He finally resorted to this last option, but he told me what he did. I couldn't blame him, actually. Besides, he'd been presented with the same danged problems so many times, he'd just memorized the answers!)
Although there is an option to "give up," this does nothing for bailing out of the topic altogether.... and ultimately, all those wrong answers really hurt the running score and frustrate the heck out of the kid.
Lastly, EPGY operates with a fixed problem set, so a kid stuck in one of these loops will eventually be faced with identical problems... over & over.
Other programs, like ALEKS, will allow a kid to back out of a topic at any time and move onto something else of the child's choosing. This way, the student can wait to get help from a parent/teacher at a later time, but still continue to make progress in general. Also, ALEKS uses a dynamic problem generator, so that the child will rarely, if ever, see an identical problem twice. (While the program might repeat a problem's setup by asking again about cookies shared between Adam, Bobby and Cindy, for example, the numbers involved will almost always be different.)
I am disappointed that a prestigious university like Stanford -- especially given the price of the program -- has not updated their software in what seems like decades. While I'm very happy with the breadth & depth of the topics covered within each grade level, they really need to bring the math program functionality into the 21st Century.
Ideally, they would keep their breadth & depth while employing the interface and AI used by ALEKS. Marrying these with lectures from Dr. Burger over at Thinkwell would be superb.
The best solution for us turned out to be quite simple. We arranged with his teacher to spend his math time in class doing homework, and then he'd spend his homework time at home doing math. This worked out great for DS, but good grief, did I have to learn a lot of stuff I'd long since forgotten (and had no particular desire to learn again!!!!!).
