The claim that Las Vegas or Orlando have culture beyond pots of yogurt in the mini-marts is laughable. Austin's culture is slowly being bled away by the same rising costs of living that afflict other tech hubs, but there are still wisps of it outside the 6th street tourist area if you look for it according to those who still remain in the area. You would probably have made a better claim by going with the Raleigh-Durham area and Charlotte.

Disney/WDW and Vegas casinos are globally recognized powerhouses, on par with Hollywood, Broadway, etc.

Just because it's not "high culture" doesn't mean it's not culture.

I grew up in Atlanta. I just wish in-the-perimeter wasn't such a ghost town. I think this is changing with the massive number of apartments being built lately (and the Beltline), but it would be nice to have more of a "bustling" downtown (compare the number of pedestrians mid-day in SF vs mid-day in Atlanta). But then again, I've always been partial to the concept of European walking cities.

When I visited Atlanta 20 years ago, staying in a downtown hotel, I was surprised by how empty the city got after 5pm. It was a huge contrast to NYC where people actually live. It sounds like this is actually changing now.

How are the summers (temp/humidity)?

I don't have a specific answer, but rather a general suggestion: weatherspark is a site with pretty thorough climate data. It shows average high and low temperature and humidity throughout the year, as well as 10/25/75/90 percentiles for each. Also does wind and precipitation. I miss their old weather dashboard like crazy, but the climate data is still good.

Awful on the entire East Coast. Hot and overbearingly humid.