we always leave our CCs and insurance cards in the safe at the hotel and never had a problem with charging to room with the KTTW. we were part of the MB pilot in September, and didn't have any charging problems, but i understand they could be glitchy. during the pilot, we had out MB, IDs and also carried our APs & DVC membership card. i expect that we will continue to leave CCs and insurance in the safe and only carry MB, ID and DVC card. I expect if there was some technical problem with the MB at a table service they could call the resort and verify charging privileges. If we got stuck at a kiosk or CS, I think we would manage. I also have my insurance info saved on my phone.