I sailed out of Mobile, in order to sail on the final cruise of the Holiday.
It is a very nice city, with a nice terminal. It was so much nicer than the glorified warehouse that Jacksonville uses for the Fascination. Mobile seems to be ideal for a drive to port, but not so convenient to fly into.
My biggest complaints about Mobile are its airport and airport services.
1.) The airport is about a 45 minute drive from downtown. That would not be an issue in itself, but there is no major highway connecting it. You have about 25-30 minutes of stop and go city traffic to get from the airport to the Interstate highway. Once on the Interstate it is smooth sailing (no pun intended).
2) Secondly for those of us who wished to fly in the day before and rent a car, They would have charged a $40.00 drop charge to rent at the airport and drop downtown. Maybe I am spoiled from a bygone era, but I always thought that you could rent and drop a car in the same geographic area (city) with no drop charges. I once rented a car in FLL and dropped in MIA, and there was no drop charge.
3) All of the taxi cabs seem to be based downtown (see point #1 above). I rented a car and returned it to the airport. It took 45 minutes for a cab to come from downtown to the airport (in hindsight, I should have paid the drop charge for the rental car). If you arrive on a scheduled flight, then there will be taxis waiting, if not then you may be waiting for a while.
Point #1 might be wishful thinking, but if Carnival does negotiate a return to Mobile, they may want to ask the city to work on points 2 and 3 (at least when the ships are in town).