When I compared the out-of-the-box Jext and Jedit about a year ago, I thought Jext easily won as a simple to use editor. The user interface of Jext is particularly strong, where-as the long menus and terminology of Jedit is confusing - I *never* heard of folding prior to Jedit.
As I saw it, Jext's advantages were:
-Extremely easy to use (compared to Jedit)
-Supports the idea of workspaces, which allows you to switch between projects w/o having to close all of the files or lose your place
-Uses a tabbed open file interface - Jedit offers this as a plugin, but its not as good as the 'native' feature in Jext (less intuitive)
Since then, Jext development has stalled somewhat. There have been some long-standing bugs (particularly in using plugins w/ Web Start), and Jedit has continued to add features. I would really like to see Jext development continue, fix some Web Start issues, and start adding some of the features of Jedit.
Conversely, Jedit could really improve by making the UI more approachable, taking some lessons from Jext. One suggestion for Jedit would be to limit menus - possibly allowing the interface to switch between different modes for different purposes.