I've currently got 3 birds, and my coop is right next to my house and in between my porch and my deck. Their coop/run is on sand. When I let them on the lawn as we were building the coop, it did get pretty stinky in those areas. Every day I hosed down the place they'd been in their tractor to kind of break up the poop and help it dissolve into the ground, but I still noticed a smell, and the flies were pretty bad in those places for 3-4 days afterward.
Now that they're in the coop/run, I scoop their poop out of the sand every day. The only time I notice 'chicken smell' is when I'm in the process of scooping poop...and that's probably because I'm in close proximity to a quantity of it. However, even then it's pretty slight. I don't notice any smell at all when I'm hanging on my deck or porch. The birds themselves seem to have less of a smell, too. And the sand-covered poop definitely has a much less strong smell overall than the uncovered poop decomposing on the lawn.