Using Piazza has dramatically improved my email inbox management. Program questions for over 500 students are never-ending and all are handled on Piazza by instructors and TAs collectively, leaving my inbox available for course level communication with other instructors, TAs, and those students with specific grading and exam questions.
Yes, we have been enjoying using Piazza and the students (and my TAs) also thought it worked out very well.
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 Desire2Learn, users are automatically signed in to Piazza, so there's no need to remember a separate user name and password.