I can understand why the OP prefers AT in this case. I don't think it gives him a better end product, but it's a LOT quicker.
For the things I do, I prefer Melodyne by a large margin.

Having seen both in action let's agree to disagree, once you hear the results and understand the working methodology is so much more than pitch correction, I suspect you will soon change your mind. Like everything the paperwork doesn't do it justice.

Part of me is VERY afraid that once I see ALL the things Melodyne can do, I'll be tweaking every single track and never actually complete a mix!  Pandora's box!!!!  Lemme go check out some of their online vids....  ;)

This is not a bad tool to try.  Not nearly as powerful AT or melodyne but will sit on a track  and is free.  You also get some great freebies in the bundle:
 
http://www.meldaproductio...duct.php?id=MAutoPitch

I have much work with not very good singers :-) and of course No AT... only Melodyne and... thanks to Cakewalk and Celemony... only as RegionFX now. However, if you are working with good vocalists maybe to use AT preferable, but good singers often do not require pitch correction :-)