I checked out Nyambe and it's interesting, but I don't like how most of the classes are set up.
I really dig the orisha that are presented, and the idea of the mchawi (sp). Alot of the monsters are really cool too. But what I don't like is how the classes are so radically different from their core setups. I understand that there aren't going to be paladins and bards, but making prestige classes for monks and rangers makes me feel like this is someone's 2E homebrew that was shoehorned into 3E.
Further reinforcing this impression are the different fantasy tropes meshed less-than-seamlessly within the game, such as the presented races. I'd rather have dealt with an all-human game than cramming D&D's round races into an African setting's square hole (after all, in Oriental Adventures, who really plays a nonhuman?).
Sorry for the mini-rant. Nyumbani looks cool, cooler than Nyambe, and I may just check it out for an upcoming campaign.