Quartzkyte is registered there... or someone using his name... i guess he could give us some insight dfmurphy... nice call.
Ive heard of this before, it is an editor similar to tiny_MCE. Apparently lighter than tinymce, some users liked it more than tiny... i dont know... i dont even use tiny, lol
The FCK-Fusion is only the last version of PHPFusion, but instead of Tiny editor Uurbana has choosen to integrate the FCK-Editor.
The great advantage of using the FCK-Editor, is the image upload feature. In the FCK-Fusion you are able to upload images, files or Flash directly from the editor, a feature you need to pay for if you want it in Tiny.
I have been using it for more than a year, and I love it.