This race is everything for everyone. If you are an elite runner, come run against some of the best runners in the world. The prize purse is huge and Kenyans come out for the race yearly. There are a TON of elite runners. If you're a walker or a slow jogger, it is a great race for you too. At many of the aid stations, people are offering beer and margaritas, so you could make it a really fun morning if you wanted to. There are TONS of spectators all around and you run through GORGEOUS New Orleans.
The post-race events are amazing too. There's tons of beer and food and is a great time. Overall, the atmosphere is one of a great party, but there are so many great runners there, that you may just grab a PR. This year, I think there were something like 18,000 runners running this race. It is an event and is well worth the drive/travel if you need to. It is what everyone loves about New Orleans!