We live in relatively close proximity to our neighbors (our properties all join at the back corners right where our coop/run is). We have seven hens at the moment, have had them for a bit over a year now and so far no stink whatsoever.
I keep straw or hay spread out in the run to keep mud from occurring. It does a really great job of preventing odor. They love scratching it and it's super easy to just throw a bale in there whenever the current layer gets thin and let them do all the work of spreading it around.
In the coop, I have been using pine shavings which I keep about 8 inches deep and stir up if it gets dirty. I have never had any odor whatsoever coming from the inside. I only change this out once a month.
I will be putting a poop board in there this spring and, as the PP suggested, will be using SweetPDZ for the "sand" on it. Heard the stuff works wonders.
Overall, if you keep the ground from getting soggy and keep the litter fresh, you will not even notice they're there.