I feel like this is a must-have.
The audio to harmony or melody in Ableton Live 10 is considerably more accurate and less time consuming to edit than Melodyne's various results. Melodyne tends to focus on too large of a range, which results in combined rhythms that are baked together with drums in the same frequencies. It often creates inversions and changes octaves that you don't audibly hear in the audio it converts. Don't get me wrong, that is useful at times but usually the time it takes to edit and the resources that Melodyne can add to a session get to be a bit of a headache.
The only algorithm that is as accurate compared to the audio conversion option included with the standard version of Ableton(which cost less than the Melodyne with polyphonic algorithms), in my opinion, is the one for percussion. Other than that, it really is only consistently close in accuracy for concise editing for vocals or simple chords/melodies.