If the seatmap looks pretty open, I probably wouldn't bother paying for Coach Choice and instead as the Gate Agent to change me to something closer to the front. Also, as reported before Coach Choice seats are open to all passengers at 24 hours out, the reason for no difference between Coach Choice times for elites and non-elites goes back to the conflict over the program when it first came out, I would describe it in detail, but it is not germane to this discussion and don't want to revisit the unpleasantness...