Well, I had 12C booked on a 320. Checked in and still had 12C. Checked back 2 hours later to see where I was on the upgrade list and bam, equipment change to the other version of 320 with no row 12. They put me in seat 37D. Only thing left in E+ was 1 center seat. I called (got a USA call center) and they switched me to the flight leaving 1 hour earlier and got exit row aisle. yes, I pulled a little DYKWIA by saying not a very nice way to treat a million miler by putting me in the last row of the plane because of an equipment swap. I did say it in a joking and fun manner and she took it that way. Lady was very nice and even made the suggestion of the earlier flight as it had the exit row aisle. She put me on hold for a while to uncheck me in, swap me to the earlier flight and check me into it then sync my reservation so it would not destroy the remaining legs (this is my outbound). Not really happy about leaving an hour earlier as it means I have to get up at 4am instead of 5am. But hey, at least I will be comfortable now.

So word of caution, never book row 12 on a 320 if you can help it as it may change to the other version of 320 that doesn't have a row 12 and then you will get put in the last row of the plane.