Nick M
Chuck Norris is my uncle
I use melodyne studio for natural sounding pitch correction. Autotune gets the effect type stuff done(core singers and T payne). Melodyne is very powerful but you really need to correct the detection especially if it is an aggressive singer. Once the detection is in place, its great. I never had a glitchy part I could not fix and make perfect with melodyne, just some working of the detection and processing.
But, you should have both.
But, you should have both.