The new debarkation process is a vast improvement. On the Oasis I had luggage to pick up in the terminal and was still off the ship and sitting in the bus within 9 minutes, and that included customs. Actually the self-debarkation people took longer since there were so many of them. We were delayed a few minutes because of them. Their line was the full length of the promenade. I went to my assigned departure area and they escorted us out when called. As MC says, it was only us and you had to be in the designated area to know you were being called to leave. The funny thing was there were self-debarkation people on the bus I boarded, so they didn't gain any time.
Also remember that self-debarkation means you and your party can handle ALL of your luggage with no assistance. You have to be able to leave the ship unassisted and bring all your stuff with you. If you try to push things with lots of luggage, you cause a problem and can also catch the eye of Customs.