[Mushroomagical]

I do freelance sound design and editing in Scandinavia, and I use both Waves Tune and Antares Auto-Tune. I frequently use Waves Tune for quick fixes of background vocals, especially if I am in a time-crunch and the singers are relatively 'in the ballpark' (the Waves GUI is great). For lead vocals, however, I tend to use Auto-Tune. Why? Because I can achieve a more natural sound with Auto-Tune. I have done many comparisons with the exact same vocal tracks, and I can always get good results with Auto-Tune. I find that with Waves Tune at certain points the sound is a bit tinny, that same sound that you get when you cut out selected partials in the overtone series. Formant correction in Auto Tune is a bit better. It's very subtle indeed, but noticeable to the trained ear. In any case, both programs are great, and the Waves GUI is spectacular. The graphic mode in Auto-Tune is, however, getting better, and the latest release is definitely easier to handle.

Mushroomagical's recommendation: if you are doing high-end professional jobs where you absolutely must have a very natural vocal sound, I'd go with Auto-Tune. If you are doing electronica or some style where you are coloring the vocals with other effects, you might check out Waves for the the easy-to-use GUI. With Waves Tune, you can get working right away even if you've never used the program. With Auto-Tune, you might need to put in a bit more time, but the results are stellar (the majority of pop vocals you are hearing on the radio have been corrected with Auto-Tune).

I am very curious about Melodyne -- never tried it -- perhaps I'll check out a demo if one is available.