[FIRST WATCH THE VIDEO BEFORE READING THE REPLY]
People who sells the plugin show you a studio song, to which they applied an EQ (boosting the mids and reduced the high and lows) and I suppose some other effects. And, after that, they show that same song sounding amazing by just using this plugin.
What happens is that the program just enhance the recording up to an optimum sound based on the information the song already contains. It won't create any harmonics or frequencies, it'll just make louder hidden frequencies. It may be good for enhancing shows, but don't expect a life changing result.
That's my conclusion out of that video. I really hope I'm wrong and it improves greatly those great recordings that need some magic.
You cannot put clarity into something when it isn't there to begin with. It is like claiming you can separate multi tracks from the regular CD. It is all mixed in. You can use EQ to highlight frequency but that is about it. Your ears do a much better job of hearing the bits you want to hear..
This reminds me about what happens in some movies - when they get some grainy photo, call on the wizz-kid, who proceeds to hit a few keys on the keyboard, and somehow they make it all clear and sharp.
If the information isn't there to begin with, no computer can create it. At best it can try to fill stuff in based on what it thinks should be there according to its analysis of the information it has. But normally it can just enhance this, decrease that, etc. Exactly as BETA said.