Originally Posted by djen
First off, I think the scream 4 already has bit reduction with it's Digital distortion type. One knob controls bits, the other controls sample rate.
As for Melodyne, check out the link below. It's probably one of the most realistic pitch correction tools thanks for the formant shaping which allows even long stretchs or vibrato to sound natural.
Melodyne demo and videos
I have to upgrade my Melodyne. I love it.