Something I think is cool; you can figure out a little about someone's original language from their accent.
So if West Indians have accents similar to people from not just Africa but completely different parts of the continent, you get an idea of how Niger-Congo group languages sound and also how HUGE a group that is.
But AAVE doesn't sound like West Indian/African accents. Which makes me wonder if AAVE actually reflects whatever not-English-not-southern accents Americans had before the 1800s.