Draft’s own description of itself is "Rich Text Editor Framework for React" and is more comparable with Parchment[1], both being a foundation in which you can build a rich text editor. But there are many pieces missing for it to be a full fledged editor like Quill.
* UI Draft only has buttons you can toggle for formats. There are no dropdowns to select which header size—just six h1, h2, h3, h4, h5, h6 buttons. There are no tooltips or link, video, or image UIs to assist with editing.
* API - Quill’s API is designed for the editing use case. Draft is built on React and inherits many primitives and ideas that are more appropriate for websites, rather than linear content like text. Which APIs is nicer for which use case may be subjective so I will just link Quill’s API’s [2] and Draft’s API [3] and ask the reader to think of some common tasks, like making a range of text bold, and try to figure out how to accomplish these tasks from reading through the respective APIs.
* Markup - With the exception of nested lists, Quill’s markup is clean and semantically correct. Draft uses <span> tags with inline styles with lots of attributes for bookkeeping.
[1] https://github.com/quilljs/parchment [2] http://quilljs.com/docs/api/ [3] https://facebook.github.io/draft-js/docs/overview.html