for a free effect this is a must-have. it corrects pitch even better than the "real" autotune, the only downside is that it theirfore distorts the sample quite a lot, but if you go for a robotic voice anyway it doesn't matter, does it? i especially love how easy it is to get to new, wide and unique voices with the formant knobs, transposing and panning. singing with this plugin feels like a bob ross painting. the ultra hard pitchshifting is also useful if you wanna make your voice sound like an eguitar. just use this plugin on its maxed out settings and put any huge guitar amp VST behind it and you feel like a skillful guitar solo.
Yeah, that happens all the time, even with subtle settings. my workaround is that i cut off the highend and leave the original highend in it. that burries the grainyness in the mid frequencies under the illusion of cleanness a bit.