Piano/keyboard people: What's better Casio LK-100 or WK200?

My parents were planning to give my son the LK-100 and the piano teacher is freaking out because they should get the WK200. Should I make my parents return the one they got? They were so excited about it. I know it only has 61 keys which I guess is a drawback and teacher keeps on about layering music on the WK200 and how it will grow with him.