Using it with the Ion keyboard works beautifully. It's very cool to see and hear the teacher say "these keys" and those keys light up on the keyboard as he plays them. The keyboard has two on-board speakers through which you hear the piano and the teacher, and the sound reacts to how much pressure you put on the keys. Pretty sophisticated for such an inexpensive product! The problem, for me, is the instruction.
I have zero experience with piano and it would help to be able to slowly roll the instruction backwards to repeat just one segment… hand placement for a chord, for example. As it is now, you can stop/freeze the image on the iPad screen, and hit the play button to continue, but you can't "slow rewind"… it has to start from the beginning. Another problem for me… It's hard enough to learn the chords, but the finger placement is shown how it should be, but then adapted to fit the 15-key keyboard, making it very confusing.
Another problem is the teacher. I like him and his easy-going manner, but he should have read from a script, or at least notes. He appears to be "winging it", because of all the times he corrects himself. (Why didn't they just edit out the bloopers?)
All-in-all it's a brilliant concept and implementation, but the instruction is not well thought out. In any case, it beats trying to learn from a book.