I gradually upgraded over time from Essentials to Studio via the other editions (So Essentials to Assistant to Editor to Studio).
It's important to consider that even the most basic Essentials edition allows you to do tuning and pitch correction and gives fantastic, first rate sounding results. So definitely consider what you actually need from the tool, and whether you already have that in the edition you have - especially if you're already at Editor level.
For myself, prior to each step of my upgrade journey, I had found myself wanting a bit more; some feature or other from the next product level, such as to fix timing or edit polyphonic sounds etc.
And so it was from Editor to Studio. I really needed to be able to have multiple tracks visible at the same time, which is a massive workflow upgrade and, therefore, time saver - especially for things like precisely aligning vocal doubles and/or harmonies. Of course, it's technically possible to do this track by track individually, but the workflow for that is pretty horrible and somewhat frustrating. So for this reason alone, the upgrade was absolutely worth it to me.
In addition to that, the sound editor in Studio allows one to do some really creative things, so while I didn't get the upgrade for this feature, it's definitely a cool and unique tool to have access to.
In conclusion, for me, the upgrade was definitely worth every penny to have access to the full gamut of what Melodyne has to offer.
