I'll tell you from first hand experience that I do like non-US cultures better but there are some fine lines the collectivist/family-oriented cultures like the ones found in Nigeria do cross that I don't like. The family will most likely try to micromanage the heck out of the relationship partly because they don't want their precious one to stray for from their expectations. American cultures like Black America and Chicanos are more laid back in that respect (mostly) and sometimes you understand yourself better with them. I've dated a Chicana girl and then a Salvadoran girl, the difference in family is pretty similar to what I experienced. The Chicana girl's family was less hands on, they let us do what we wanted and didn't really try to interfere. The Salvadoran's family was mad cool and caring but sometimes I felt like they were too strict on her and it cramped our style. They were cool but sometimes I didn't understand them since I was born and raised in the US, around US culture. The Chicano family in that respect was cool, they understood the struggles I'd go through in the US as an American born Latino. The Salvadorans were very loving and had great food but I felt at time they didn't understand me perspective, especially from a social tip.
I would venture to say, you might get that same feeling between dating a Nigerian and Black American woman. I guess my Naija and Black Coli brothers probably know better
Just my own experience.