Lot of threads on here about Nashville where people have discussed things.
It could potentially be pretty cold and or icy and snowing when you're there, just a heads up. Nashville truly gets 4 legit seasons.
I'm a fan of midtown personally. Closer access to areas like 12 South and the Gulch without having to stay downtown. Sometimes it can be a PITA to get in and out of downtown. But if most of your trip is spent there, then no issue staying down there.
I could go on and on, there's a lot for everyone there depending on your interests. What are you looking for on the trip?