Honestly, I think that it would not be as helpful as we would assume. State-wide crime rates are just too wide-ranging. A county-by-county map, or even a city map, would be more informative, and contrast it with a map of those cities that have stricter gun laws.
But really, everyone knows what the map will look like. Most cities have far more violent crime, and higher violent crime rates, than suburban and rural areas. There will be a few variations, of course, but the pattern will dominate the map.
Sometimes I wonder if we just might need different sets of rules for urban vs suburban areas. (Recall that America's largest city in 1776 was Philadelphia... at 50,000 people.)
While I agree that urban areas are more likely to have a higher crime rate than rural areas, state wide averages of Right to Cary vs no right would be illustrative of the benefits of Right to Cary/Self Defense (Stand Your Ground) Laws.