Just a couple bits of AP info I experienced during a visit last week...
1. If you are both an AP and a Resort Guest, the park reservation system prioritizes your status as RG over AP. This meant that on a day EP was sold out for RGs, but open for APs, I could not switch my DHS reservation to EP. I called the VIP line, who transferred me to IT. About 35 mins later it was taken care of. If park reservations stick around, they reaally need to fix this issue.
2. I used my old AP card in many places for my discount with no issues. But on my last day, a CM told me they want us to use
MDE to show our AP status for discounts. If you insist on using a card, they want you to get a new card from GR or a ticket window that shows your expiration date. GR told me they don't think such a card exists, though; I had to leave so I didn't wait around to find out. I'll just use MDE if they ask in the future. But this was news to me - and to the person at GR!