As an instructor in music theory, I'd say this program has some quirks. First, there are some weird things within each module: for example, when setting up the key, the solfege module uses bad voice-leading (especially in minor). I realize that's not the point of the exercise, but I can't recommend something to my students if it isn't mutually reinforcing with all the other things we do.
Finally, the modules as a group are a bit bizarre: one or two would be great for my aural skills class, one or two for written theory, etc. And the huge range of skill level involved (for example, "identifying notes on the piano" versus "identifying non-diatonic scales") is a bit baffling, and doesn't seem very targetted at any group in particular.
Still, well designed and easy to use.