It seems like a good tool for beginners who don't have a complete grasp of diatonic chord progressions and roman numeral notation.

It does however look like it's highly limiting if you're planning to rely on it as your primary source for creating chord progressions. The reason why is because a I-IV-V chord can be played in many different inversions and while this doesn't necessarily change the roman numerals it DOES change the sound and the voice leading. All the chords in the overview video are in your basic root position which sounds incredibly formulaic and boring. There is no voice leading at all whatsoever or use of inversions.

When the bassline gets added in the video it is once again simply following the root position of every chord. This is limiting your ability to create melodic basslines because you don't need to have just one note playing per chord.

It also doesn't take into account (at least from the video I saw) more advanced composition concepts such as modal interchange, modulations, counterpoint and undiatonic chord progressions. It's impossible to create counterpoint using all root chords.

Overall I would say use it as a tool to get familiar with very basic diatonic chord progressions. Once you're done playing with it and are ready to move on I would ditch it ASAP.

Well, I don't know what to think about this software, I've seen the video but unfortunately there's no a trial version available, but until now I'm fine with the possibilities of the Xfer Cthulhu and Ezkeys.

Does this kind of miss the whole point of producing your own music? Seems a little like painting by numbers if you get my point.

Although saying that looks like a useful tool for newbs like me to get their head around chords progressions etc