I think the issue with Melodyne "disappointment" is that Melodyne
Essential is not as full-function as V-Vocal. As a result I continued using V-Vocal when X3 first appeared. However, after upgrading to Melodyne
Editor I haven't used V-Vocal. It sounds better, is more reliable, and does polyphonic pitch correction (I've actually used it on slide guitar - the slides were left alone, but where the notes "landed" was corrected).
There are two features Editor doesn't have that were part of V-Vocal. One is LFO-based vibrato, but that can be accomplished by using the Sonitus modulation plug-in for vibrato. The other is the "pencil" tool for drawing in pitch changes. However, Melodyne does have various pitch correction and note splitting tools that are more complex to use, but overall, to my ears give better results overall.