I've been taught that aquí and acá are completely interchangable.
From personal observation, acá seems to be used more often than aquí in the context of "I live down this road." Example:
Vivo por acá.
I don't think I've ever heard a person say
vivo por aquí, even though I think they have the exact same meaning, right?
I'm wondering if there are any guidelines for when one is preferred over the other.