to me, the old south ended w/ the end of slavery, which might not be technically true or what you're looking for, but as a NYer, it's just the image that pops in my mind.
yes, the images of the "old south" to me are pretty negative, the images of the "new" south to me are... disney, florida beaches and beautiful, historic cities - which I haven't even been to, but I think of say Charleston, Savannah, etc, and would like to visit, and would feel like I would enjoy it and see lots of southern charm. I don't think of the old south when I visit the south now though, unless I see a rebel flag flying or on the back of a pickup truck (but, we have some of the pickup trucks w/ the rebel flag in NY too - but more rarely).