Superworms are discussed quite frequently in this hobby. Here's enough reading to create an opinion of your own:

http://www.frogforum.net/search.php?searchid=386327

The usual arguments is that they have a hard exo-skelleton which can cause impaction if feed to often (in other words not a good staple food), and that they can bite. Therefore, it's recommended to crush their heads before feeding them to a small frog. I have no personal experience with zophobas, so I can only quote what others have said about it.