I didn't feel like I needed to have read this after I read it; I think the other work you encounter that talks about the panopticon does a pretty good job of summing it up, and I will be honest that I did not really understand the fragment on ontology. But I do appreciate the return to the text, and the introduction by Miran Božovič did a good job with the framework and exploring some of the points of the writings that I probably would have missed otherwise. If you're REALLY into like returning to the original text, or have other interests in Bentham's larger work (oops I don't) then obviously it makes sense for you to read this, but if you've already read the other works and are like "great" then you are probably okay on this one.