Depends. Domestic - always. International - never when departing ATL, but often when I return.
Why?
Domestic - Yes bc almost always get a drink tix. Also, I never ever check luggage.
International leaving from home - No bc I like to try to sweettalk my way into an upgrade at various counters (works about 50% of the time). Still never check bags.
International return - Yes, when allowed, because I usually can't sweettalk agents into an upgrade (unless at AMS) and I am just usually ready to make short work of getting home.
*sweettalk = convincing them to allow me to use miles or SWU when DMD swears its not available.