"Distance between nodes is not always the criteria for adding more nodes in a network. The Z-Wave radio signals may bounce off metal objects like mirrors or appliances and cause two nodes that are only a few feet apart be completely unable to talk to each other due to reflections of the radio signals. Adding more nodes in the mesh provide alternate routes to nodes that otherwise might be in a dead zone due to these reflections cancelling out the radio signals."
from the Seven Habits of Highly Effective Z-Wave Networks for Consumers - Dr. Z-Wave (a little outdated article, but still from one of my favorite Z-Wave gurus)
@e_ryherd thank you for your insightful blog posts. Always looking forward to your next article 
