Just to clear up any confusion: this is not the same as the Guardian’s “Scribe” project (https://github.com/guardian/scribe). I believe Quill did used to be called Scribe, but they are not the same. (Similar in purpose - take your pick.)
I love scribe, it's the most consistent of all the editors I have tried (and I have pretty much tried them all). Would love to see image support though. I know there is a pull request pending for some time on this issue but hope it can make it to the core. Even nicer would be to have hover controls on inserted image (using shadow DOM I presume) that allow modifying its attributes (right/left align, alt text etc).