My new job has me flying back late, and my layovers are usually in Atlanta. The past 2 times, I have arrived late due to delays, and had to spend the night in Atlanta until my rebooked flight left the next day. I know that there are no SPG properties on the ATL SkyTrain (which would be really nice). My research has uncovered there are 2 SPG properties close to the airport. The Sheraton and the Westin. Any experience from those who have stayed at both these properties? How is shuttle service? Upgrade experiences? Thank you.