I'm a researcher at UMC, and I've been accepted into the class of 2012. U of Miss doesn't participate in the US News survey; Dr. Case (D of A) told my husband that they don't agree with the method of the survey. Anyways, to add to the stat info above, Dr. Case also told us that the MCAT scores for entering students at UMC are below average for matriculates, but that by Step 1 the students score average nationally, which provides evidence that the instruction at the school is exceptional since they take below average students and raise their credentials. They just changed the curriculum in the last few years, and Step scores did not decline during the transition. The curriculum is still too new for me to have info on the Step 2 scores. Emory is moving to the same curriculum (systems based) as UMC this year.
Hope that helps a little. Also, people complain about Jackson a little bit, but it's really easy to make friends, and if you have friends you won't get bored. You'll get to see a lot and perform a lot of procedures in school.