I second the interview prep, but if you've already done one, you'll be fine.
Be personable and positive, you're personality will shine through if you're honest. Just relax and enjoy the interview. It was a little different, but I don't have a lot of experience in interviewing.
Show plenty early. I rented a car when I came down, but it's not necessary. Most of the hotels, and the ones listed are great ones for the interview, will take you there. Remember, your interview begins the moment you leave your house. If you fly down on Spirit, be very courteous TO EVERYONE, introduce yourself to the crew and let them know you're going down to interview. Everyone should offer words of encouragement because we all want you to be successful.
At all times you're at the interview center, realize and understand you're "interviewing" at all times, even when you're not talking to someone. Don't think "conspiracy theory", it's just a mental trick to prep yourself.
Best of luck to you and all the interviewees. Don't take all the negative stuff on the board seriously, this really is a great place to work.