When I was taking classes for recording engineering we would do these during every class just for fun/practice. It would basically just play you white noise and then drop/gain on certain frequencies and tell what each one was. Then they would play it randomly and you had to try to guess which freq. they were cutting or gaining to. we didn't do any of the other ones. I'd recommend it if you have the dough though. My professor who knew what he was doing when it came to recording, definitely backed this product.
