I assume you must be going into T concourse. AA and UA got some gates there for their business-oriented flights, but that's atypical and most people get to deal with either concourse C or the end of concourse D. Those concourses haven't gotten the same attention as the DL ones.

If you fly the ULCCs you often get the oldest terminal or the least-wanted place in the pecking order. Though with MIA you get to see the pictures of 50s and 60s celebs that went there. With FLL the old concourse H used to be the "Black Hole of Calcutta" for Spirit passengers, but now they have space in the adjoining concourse as well.

Sometimes, though, like SEA and LAS, some of the legacies get booted to satellite terminals and you're better off with the older concourse.

The difference usually is in which places attract the best restaurants and other vendors. Northwest tried to do that for their hubs when they were around...even in MEM.