The med center is huge and serves as the primary referral hospital for a humongous area. They definitely get their fair share of ASA 3s and 4s and you'll get great trainig. The PD was very friendly and I definitely felt a great 'Southern Hospitality' vibe to the program. You're out of the ORs at 3 everyday so if you're not studying you can't blame anyone else.
I see two main downsides - #1 is research, if you're interested. It looks like Panni is really trying to turn that around, I think it might be one of the reasons he was brought in. I heard he did some good clinical stuff in Florida with Suggamadex, and he's hiring his wife, who has a very strong research background, as director of research for the department. That said, I persnoally don't think research is a big deal during residency, for me residency should e all about becoming clinically proficient and independent. Mississippi will provide enough infrastructure to teach you how to do it if you're interested. You can always research later.
#2 location is not ideal, at least in my books. If you're cool with a quieter city though, Jackson might be right up your alley.
Also, be aware that a lot of Mississippi MS IVs want to do gas this year, so there may not be as many positions available as it seems.