C-2 will almost invariably be the busiest checkpoint at this time of day, since it is both the most centrally-located and closest to the AirTrain station. I have had the most success getting through C-1, but I would expect all checkpoints to be fairly busy at that time of day.

Furthermore, If I were you, I would try to go through the EliteAccess line by showing your bmi elite card along with your BP. I believe the overwhelming odds are that you'll get through, given the general indifference I've experienced from the contract agents there as to properly administering the priority security line.

(Just to give an example, certainly not a remote one, last week at the C-1 checkpoint around 4:30pm, the general queue had backed up almost all the way to the entrance, while the EliteAccess line was maybe 30% full, and moving. The agent proceeded to move the barrier to open the general line, close off the EliteAccess entrance, and dump 50-75 people from the general line into the EA queue, right in front of me. When he reopened the EA line, letting me and other equally surprised travelers through, I asked the agent if this was standard procedure, to which he replied unintelligibly, and I moved along. The EA line was now virtually full, and the agent's brilliant decision cost me about 15-20 additional minutes of waiting behind dozens of generally disoriented and clueless travelers. This is why I have zero faith in the lackeys that regulate access to CO's elite lanes at EWR.)