I have studied and taught this subject for years (in fact I have a PhD in folklore). So although I only spent 15 minutes perusing the site and have not actually used it for a class, I am familiar enough with the material and similar sites.
This site allows students to get familiarized with the idea of heroic quest stories and to read both classic examples of such stories and those written by other students (a good idea). It's a well-designed site with nice graphics easy-to-use links. My problem with it is that it is all based on Joseph Campbell's ideas about the hero. And Campbell was not a very good scholar of folklore because he usually uses only PARTS of stories, completely extracted from their contexts, to prove his pre-existing theories. He also completely ignores other scholarship (in print) from his own time on the same subject. These are two definitions of bad scholarship. Also, his information and assumptions are sometimes inaccurate, or at the very least incomplete and slanted.
Nonetheless, Campbell clearly appeals to many people and is often responsible for getting them excited about studying myth. So it is good to have familiarity with his work (just not to rely solely on it0. And as I said, I do like the idea of reading contemporary versions of the hero stories (written by students) that this web site includes. I often incorporate similar assignments and find them very effective, but haven't included students' stories on my website. That element of this site is nice.
If I were to use this website for my hero's quest class, I would simply have to really emphasize what is good and BAD about Campbel and be sure my students also understand and are accountable for the many other ideas of the hero and myth generally. I have a website that does some of this: http://www.faculty.de.gcsu.edu/~mmagouli/defmyth.htm (go to the heroic patterns link for instance).
Technically the website seems well-designed and efficient.