Remember that if you have a long walk in the main (A) concourse - be sure and check to see if the overhead Express Tram is faster. It depends on which two gates are involved.

Don't just make a mad dash without checking this.

Sometimes you even walk a few steps "backward" (away from your connecting gate) to go up the escalator to the Express Tram.

Take a look at this diagram:

http://www.metroairport.com/pdf/maps/McNamGatesMap.pdf

...it will help a bunch in getting the hang of it. For example, if you were going from A20 to A72 - you would not walk toward A72 - you would actually walk back and catch the Express Tram (see the red dot near A11) - and ride the tram to the stop near A70 - and your new gate is right there.