One unexpected benefit of using Piazza was being able to watch students develop an understanding for class concepts through discussion threads that were occurring online without me responding immediately. Being able to read these threads allowed me to address topics and resolve misunderstandings in future lectures.
Piazza has worked out quite well. I like that one has the ability to enter LaTeX commands for mathematical expressions.
I love using Piazza for answering student questions; the user interface is unbelievably nicer than anything else I've seen. It is easy to enter text and easy to see what questions need answering; It is just easy to use.
Instructors can create a Piazza for their class with a single click.
Students and instructors are automatically enrolled with appropriate roles, based on the course roster.
When clicking on Piazza in Sakai, users are automatically signed in to Piazza, so there's no need to remember a separate user name and password.