I've found that the harmonizer tracks better when there are more than one voice selected. I'd love to have control over the individual levels of the voices, like you can on the Audya. AJ and I have discussed this. The simple one voice above harmony doesn't seem to follow my scoops and bends as well as the multiple voices do. I can deal with it for now. I'd rather have a vocal group than a duo if I had to choose between the two, but that's just me. I'm a 4 Freshman/Mills Bros guy.