Sorry if this has already been brought up, but the text color on the new wikitext editor looks a bit faded/unclear. When I edit using the new tool, the text in the editor is #252525, whereas the old editor color is #000000 which is much more legible (although that might be different from browser to browser, I'm not sure). I'd love to test out the new editor, but at this time I can't use it without significant eye strain. I've never had problems with the thin serif font used for wikitext, but when the color is also made unclear it's not very nice to use.
Topic on 2017 wikitext editor/Feedback
I believe that the colour was picked for accessibility reasons to avoid eye strain and contrast issues for some users. I'll ask one of the experts to comment.
I tried a second go at it today, and I've not really been having any issues. Perhaps it was a kneejerk reaction. The faded text makes it easier to focus on the line you're working on and makes everything else "disappear" and it's actually quite pleasant. Perhaps this was the intention of the designers as well.
Thank you for that; I'd be interested in how you feel in a few more days' time of using it, in case you have other thoughts / reactions that become apparent after time.