There are numerous quirks and improvements needed on the editor, including:
Quirks:
No ability to insert Style tag to define CSS just for the article
Table strangeness including table & column spacing strangeness (table width 100.58%, or something similar, column width 49.78%), suddenly adding height to rows, etc.
Default of links to open in the current window vs a new window/tab
Improvements:
Right-click functionality for better editing of elements
Viewing source code at cursor location (trying to find & edit source code to fix issues is arduous when you have to hunt through a long page's code to find what you are looking for)
Defining of additional CSS classes for the document
Find/replace in source code view
Advanced page builder functionality to really allow us to craft content the way we want including things like accordion elements (expand/contract content when clicked), drag & drop elements, additional widgets, WYSIWYG editing, etc.