I can think of a few more benefits commercially, such as the fact that a LOT of energy goes into feather production... so if it's in an environment that's warm enough, then they will either grow very fast, or on less food than one buiding feathers I would think... again that's not taking into account the amount of energy required to maintain body temperatures, if it's kept at a confortable temperature.
I agree though, the little girl's look says it all LOL I'm not in a situation where one would be practical though, my birds are extremely fond of the blackberry/wineberry/raspberry bushes (and I have no more berries - at least as high as my banty brahma girls can jump LOL)