Great to see this name added to the site! I do remember reading that the meaning "falling eagle" refers to the moment when an eagle folds its wings and plummets down in order to strike its prey, so this is a name that implied aggressiveness or bravery to the ancient Aztecs, not the defeat or death of the eagle as might be supposed.
Well, it is used in Mexico. And, it is also my son's middle name. It is different, but since my son is of Mexican desent I wanted a strong name to remind him of his heritage. I also liked the fact that is is Aztec, since his fathers grandmother knew the language.