It only started less than 2 years ago so no one has yet reached the renewal stage.
Update on DC: after landing yesterday went to kiosk the noticed that there was a dedicated lane for handing in the receipt!^ The CBP officer said that it was only a recent change and I joked that when I first stated using Global Entry the officers didn't even know what the printout was. He laughed and agreed.
This was another step in the right direct of this great program.