So I have been testing units in building dense Hollywood and West Los Angeles for a week or more now.
One of the things I have definitely found is that in an urban environment messages are often received however the confirmation return signal is lost or does not reach the sender.
At close distances (.25 miles plus or minus) I have managed to get signals through a building or multiple houses but often do not get the return confirmation on the far side.
Even height does not help if there are minor obstructions (trees for example) at distances of over 1.5 miles.
Longest shot so far has been two miles straight down Sunset Blvd however even at 9 stories up a shot to another street will not pass through the minor obstructions of roof lines to a user at ground level.