In my opinion the BusinessWeek rankings are a significant notch above all of the other US rankings, including US News. I could go on at length why if you are interested.
You have probably heard this before let's summarize these two schools.
University of Florida is a Near Elite Froniter school. It is a public university located in the northern part of the state with the nearest major metro area being Jacksonville. Univ of Florida is easily the highest prestige FT MBA in the state although one can find higher a higher cluster schools in Georgia (Emory).
Vanderbilt is a Near Elite school. It is a private university located in Nashville TN. Vangerbilt is easily the highest prestige school in the state of TN and one of the highest prestige schools in the entire South of the United States. The University is one of the most esteemed colleges in the United States, perhaps one of the top 25 or so undergrad institutions in the nation.
While, of course, I cannot tell you which school you should pick, I can say that between these two schools I would prefer Vanderbilt.