So who do address as "sensei?" Are there any other titles or honorifics you use?
In the dojos I have been a member of, "sensei" is a functional title. It gets used for yudansha who regularly teach class but ONLY WHEN THEY ARE TEACHING. I can live with "Matt Sensei" or "Sensei" during a class that I teach...but once we bow out, I see no reason/purpose to being addressed as "sensei" and I don't want other members of my dojo referring to me that way.
My own practice is to refer to senior members of our organization (ASU) as "sensei" as a mark of respect.