I spend a lot of time entering content into Orchard Core CMS as well as assisting clients with content management. The editor chosen for HTML Fields and Text Fields in Orchard Core makes a huge difference in the backend experience and each editor has its pros and cons.
I typically tend to avoid Wysiwyg editors in a CMS for 2 reasons. First, if you copy and paste into a Wysiwyg editor if often copies the HTML styles and tags from the source document in addition to the text. This is especially troublesome when copying and pasting from a word processor, like Microsoft Word. Second, a Wysiwyg editor often alters the HTML you might want to add to the contents of the HTML Field or Text Field, causing one to have to work around the editor. For simple needs and more experienced content contributors none of this may be a problem, but I've seen issues with this way too many times.
Although you may have to know a bit of HTML, I was delighted to see the addition of the Code Mirror editor in Orchard Core CMS for both HTML Fields and Text Fields. At one point I thought something broke in Orchard Core when the Code Mirror option was removed for HTML Fields. This occurred somewhere in the 1.0.0 RC2 builds. I was about to create an issue on the Orchard Core Issue tracker, but after some digging, I learned the Code Mirror option was removed because it was now the Standard editor for HTML Fields. Great choice!
If you like Code Mirror for HTML Fields in Orchard Core, you can also use it as an editor for Text Fields by modifying the properties of the Text Field. At this time, Code Mirror is not the Standard editor for Text Fields so you would need to modify the Text Field's settings manually and/or modify the theme's Orchard Core Recipe, depending on your situation.
I'm sure we'll see new editors added for the Text Field, HTML Field, and other Content Fields as Orchard Core CMS matures and more Orchard Core Developers come on board. It's really easy to create new editors for Orchard Core CMS and I look forward to new and other editors!