I have seen those demos....I wasn't impressed at all.....
IMO it's a toy gimmick... I really enjoyed the vocoder mode this demo showed on a great classic Queen song.....it was really well done. .
It is a gimmick, to be sure, and despite your views, there are many who benefited from Danny's great tutorial, myself included (I use it on clinics)...funny, but you never see a harmonizer being used on American Idol, or any other show that may feature a single vocalist...unless it was pre-recorded (studio).
If you really enjoyed that video you posted, that's great...I thought it was quite funny, and I think the guy in the video must have been joking around...no one could post something that awful and be serious.
Ian