I am learning both American and Argentine - I see them as two very different dances which happen to have similar names.
It is interesting that you think the Argentine Tango is less versatile than American tango. My experience is just the opposite - American tango really demands music with that instantly recognizable stacotto (I know, my spelling is bad). while I love listening and dancing to Argentine tango music - I have seen, and I have danced, the Argentine tango to many different types of music, including "soft rock" ballads. I have even seen it danced to swing music - but that loses a lot of the feeling I like about the dance.