Husband and I did your EXACT move 5 years ago (military). Moved from Atlanta (me) and Fort Gordon (him) to Colorado Springs.
Traffic....Ain't got NOTHING on Atlanta, even going to Vail, on a Friday, in the height of ski season (it's the equivalent of a Friday traffic day on 85/285 night sucks though since there are very few street lights). I commuted between COS and Denver for a while for a job, and it's a long drive but in all honesty traffic moves, even in rush hour. You aren't sitting in a dang parking lot every day.
Cost, that's going to depend on what part of Colorado you live in. Boulder/Denver are going to be more expensive then the Springs was, yes water is pricey (mountain desert) but at least in the Springs the utilities company is a not for profit, our utilities on our house were 150 bucks a month CHEAPER then when I lived in a place half the size in Atlanta because they didn't have all the stupid usage fees. Electric was MUCH cheaper then ATL.
Weather...this was the hardest adjustment for me. It is insanely dry in CO compared to GA, and depending on where you chose to live you can get A LOT of snow. Denver area, they would get a foot of snow in a storm, where as the Springs would get an inch or two since it sits in a protective bowl (lived there 4 years, never once shoveled the driveway). It can, and does however, snow in late May to June, and we always had our first flurries in September, you also get hurricane force winds coming down off the mountains on some days. On the flip side, you never get a 100 degree day with 100% humidity like you do it GA either.
We LOVED CO, wish we didn't have to leave, just make sure you have jobs before you go.