Noting his only membership is Aeroplan with AC, this Elite D to the left is indeed a longshot. Actually if you really want to know there is a TSA website with the average wait times at all the gates based on time of day. B is always the fastest. The sheep (99% of tourists) will see D43 and go and queue up at D walking right past the empty TSA lines. Since nobody gets a "B" then of course the non sheep use "B".

Right here: http://waittime.tsa.dhs.gov/index.html

Between 10 a.m. -2 p.m. on a Saturday: reads in pairs - time 10 -2, average and maximum by gate.

MIA-A 5 min. 10 min. 6 min. 13 min. 6 min. 18 min. 5 min. 9 min. 10 min. 25 min.
MIA-B 5 min. 14 min. 6 min. 12 min. 6 min. 12 min. 5 min. 10 min. 7 min. 12 min.
MIA-C 6 min. 10 min. 9 min. 15 min. 5 min. 11 min. 6 min. 13 min. 8 min. 15 min.
MIA-D 13 min. 20 min. 8 min. 15 min. 6 min. 15 min. 7 min. 11 min. 8 min. 16 min.