Harmonizes but don't dare trying to whistle
Works ALMOST as you would expect it should. Good effects. I wish the dials for the effects did not turn so easily, as they tend to get turned to other settings during the set while turning the pedal on and off with my foot.
Major Problem. You can't whistle into your mic while using the TC Helicon Harmonizer on any setting or else the auto gain goes wack and the whole vocal functions stops working. The only way to get it working again is to turn it off and on again. Major Bummer because I whistle in a couple of songs in my set e.g. Patience from Guns and Roses