This article is very true especially for international flights, and sometimes works for award tickets as well. I've used CHA several times for flights to places like DUB. Ironically, the flights invariably go CHA-ATL-EUROPE, so apart from the extra stop its just like buying your ticket with ATL as your origin.

The only drawback is that DL flies the little RJ's out of CHA to ATL which are more susceptible to weather, mechanical delays and full overhead bins. My mother-in-law's flight was delayed once in CHA due to mechanical and DL paid for a taxi to take her to catch the next leg in ATL

Apart from that CHA is a joy, easy to park, easy to go through security etc. And if you are living on the northside of ATL, its only 30 minutes more drive to CHA when you factor in traffic.

CLT is also a worthy alternate but I've used this only once. The 3.5 hour drive from ATL kills it for me.