I mean.... I today went and grabbed a chair and sat in their run.... I didnt notice a smell, but I might just be accustomed. I don't believe you would notice, especially if it was kept clean, but I could be wrong
Usually, what stores say, I would count in half the amount they say. If you want happy chickens, plan on 4 sqft in the coop (per bird) and 10sqft per bird in the run. So for 8 chickens, an 80sqft run and a 32sqft coop.