I rode the Gulf Breeze a few times. Once, when it was fairly new, I rode a rooomette for daytime use from Altanta to Mobile and back.
Later on they dropped the New York to Mobile sleeper.
I have always taken the train from ATl to BHM and back-- often in a day. Usually, during the Gulf Breeze years, I think I was put in a Crescent coach to go from ATL to BHM, but in a Gulf Breeze coach to return from BHM to ATL.
I recall the Gulf Breeze was more on time than the Crescent. I recall over-hearing the regular passengers in the BHM station talking about how much more on time the Breeze was. Of course the Breeze would have to wait in the station at BHM until the Crescent arrived from NOL so the two trains could join.
That track from Birmingham to Montgomery to Mobile has seen quite a bit of use through the years.
Under Amtrak, the portion from Mobile ( en route from New Orleans) to a small town in Flomaton, Al.(not an Amtrak stop) was part of the Sunset's route from LA to NOL to Florida.
Then there was the Amtrak Gulf Coast Limited from Mobile to New Orleans
Before Amtrak it was used as the old route of the Crescent and Piedmont Limited from NY to WAS to ATL, Montgomery , Mobile and NOL (by-passing BHM and Meridian. That was handled by a train called the Southerner) .
It was used as part of the Cincinnati to NOL L&N mainline with trains like the Humming Bird(already mentioned above) the Pan American and the Azalean.
The Birmingham-Montgomery portion of it was used by the Chicago to Florida South Wind( forerunner to the Amtrak Floridian)
The portion from Flomaton, Ala. to Mobile and NOL was also used by the Gulf Wind, an overnighter from JAX to NOL duplicating today's Sunset Limited route, if ever and whenever the Sunset is restored to the east.
At one time, the southbound Pan American, from Cincinnati, Louisville, Nashville and Birmingham would combine in Montgomery with the Piedmont Limited from NY, WAS, ATl. At Flomaton, the Gulf Wind from JAX would join them and then would run into NOL as three-trains-in-one.
I actually rode that long monster one day. I remember it well, It was the day Hurricane Camille also paid a visit to the area.