Well I d/l the demo and watched the (1 hour+ !!) tutorial. This is not an easy program to use, but like all things in life, you get out what you put in. Even applied to one track (song) in a typical gig, this would be time-consuming.
All the tutorial exercises are based on idealised audio files (sine waves, audio files with 2 or 3 clearly identifiable elements), so I have not seen it applied to a typical full rock/pop 'busy' mix for example.
However, I do think it should be possible to closely define instruments like drums / bass / guitar if the audio sample contains these in isolation for at least some part of the file. If you can do this, then the sky's the limit, define the layers, export as .wav files, or just mix higher/lower, or apply separate VST effects, then re-mix.
Also, it leans towards wiping out the clappers / whoopers / singers on our beloved recordings, or tape noise on older stuff.