I noticed a bug when editing the underlying html in a SimpleHTMLEditorField after clicking on the < > icon. After you click on it and make your changes to the html code, and try to save, the field reverts to what was originally there in the first place. This is making it impossible to save any changes to the html in the field.
Note, it is not a problem with incorrectly saving the contents to the db. I actually can see the html editor field revert back right in front of my eyes as it saves.
Also, am wondering why the SimpleHTMLEditorField converts paragraphs to <div>s and <br>s? This is a little irritating as <p> is the standard tag for paragraphs and I wrote CSS styles that target the <p> tag.