Yea, we were tested using it at audio school.
Ii thought it was great and very thorough. It starts with simple small band frequency boosts but gets a lot harder with compression, distortion, +/- 3db etc.
I don't know if I could force myself to sit and do it at home but if you have the dedication it is a very useful tool for training your ears.
I got 10/10 on my very first go at small band frequency boosts in music