Sorry to ressurect this thread, but it made more sense than starting a new one.
I find myself down the back (booked by someone else) on an A319 early next year. They booked it with a corporate agent and I can select seats (including exit seats) even before I put my BAEC number in.
I have booked row 9 outbound, but the furthest forward on the return in row 13. How far back do the convertable seats go? Can anyone update the sticky, which currently just appears to talk about 737 (ex-LHR) seating in ET.