I know some people really like sand. Maybe it depends on where you live and if the run is covered or not. I live on a lake and when I first got poultry, I used free sand from the lake. When dry and fresh, it was OK. But when it got wet, mixed with duck/chicken/goose poo, the sand really smelled bad. I was constantly replacing it with fresh, clean sand. It was a lot of work.
Now I only dump organics in my chicken run and let them compost in place. It works much better for me than when I used to have sand as litter.