Although I have not asked any how happy they are it seems they are happy enough when confined. I would say that access to an aviary is something that is of importance. Fresh air and exposure to sun.
Back to your last post while you and your not as agile self was logging...Did you manage to miss all falling trees and not have one land on you and kill you?
I am biased, but I do know one pigeon made a great pet for a kid....BUT a herd of pigeons was enough to make a barn a mess.