Actually, the gap shrank to about 550k after last holiday season. The XBO won by ~400k last November and ~200K last December.
Whoops. I must have punched in a wrong number somewhere on my calculator. I redid the calculations and the LTD gap as of the end of 2014 was indeed much lower than 750k. More like 520-530k. The gap as of October 2014 was still about 1150k.