I love the service with Southern Elegance Limousine. They have been very good about:
1- a flight change that meant a 12 hour pick-up difference (with 24 hrs notice)
2- a 3 hour flight delay on arrival (no notice at all)
3- a 45 minute notice EMERGENCY pick up
They cost a teeny bit more ($20 ish) than some of the other companies but the service is worth every penny.
hope that helps!

Shel