My flight the other day, 1731 from Cancun, scheduled to arrive ~ 6:30 pm, also went to Terminal B. The pilot said we'd come into C if there was space, but this flight had been arriving at B the past 2 weeks and that's where we ended up.

With no connections/checked bags, arrival at B was a breeze. Immigration and taxi lines are much quicker and the shlep from the gate isn't as long, (though I guess that last part depends on which gate you come in).