I liked it when it came out because it was new, but simply slapping the air doesn't feel as good if you actually felt you were slapping something. I liked the wii more because you'd actually hold the remote like you would a sword or a bow for example.
STEM is a lot like that. You attach sensors to your feet, waist, head and you hold two controllers (also containing sensors) that you hold in your hands (that come with several modular attachments to modify it to suit a wide array of games).
It's essential one big super refined full body Wii controller.