We also used helpers to really practice his reactions to strangers. He does still growl but well timed reprimands from the collar keeps him from escalating past the grumbly stage.
His obedience is looking fine. His Down command is comically slow but he is doing it. He is also a little pouty about Placemat. He would really rather be on the couch. But we have this week to fine tune things. He is really doing great.