I'm gonna try using Melodyne with the same AudioSuite method I use with AT.
Absolutely hated exporting vocal tracks into standalone Melodyne. Not only is it a clunky UI, but it breaks your workflow and costs you a ton of time. It's just impractical if you do this for a living.
More than anything this is about workflow. I want the one that's going to have the easiest to interpret pitch curves, the quickest correction and the least artifacts. I'll shoot them out against each other shortly!
Worst case scenario will go back to Cubase's VariAudio, which is probably the best integrated out of all of them, though terribly inflexible and glitchy.