As a community in white countries? Largely negative.

Some negatives:
- Ruining the big cities that were great before they arrived. It pains me to see all this hard-won achievement not just stolen but mutilated, all with a sense of annoying entitlement. Say, blacks often argue how they built Chicago even though they were just 2% by the time it reached 2 million people. 
- Forcing the historical population to flee, making regular whites lose influence and become more rural and marginal. 
- Reliable voters for anti-white parties and their loyal thugs. 
- Exorbitant levels of crime, as well as celebration of crime and aggressive cockiness even among the leaders. "Condemnation" of crime tends to come from ex-cons who derive masculinity points for their criminal career. 
- Everywhere I went with a significant black population, they were disproportionately responsible for unpleasant things. Shouting in the street for no reason, sleeping drunk on the subway, littering, pushing people.
- Deeply unfortunate prominence in popular culture (as opposed to the more numerous but largely ignored mestizos).
- Everything points to their relatively low intelligence, even if it doesn't stem from biological differences. This is a pretty dense community. One might joke that that's the reason they're big in popular culture, but it's more because they're so numerous in the important cities which broadcast their culture.
- Like I said, aggressive cockiness and disregard for the truth seems to be a thing. It may be efficient, but it disgusts me. Reminds me of native Caucasians on steroids.

Some positives: 
- I like it that they bring attention to race and race-based nationalism, showing the impossibility of assimilation even after centuries of communal living. It helps white think in racial and not national terms.
- The impossibility of blacks to assimilate in Canada, the UK, France, and other countries shows that it's an essentially universal barrier. 
- They demonstrate how worthless most Christian churches are when it comes to defending whites because they're constantly pandering to the super-Christian blacks. Or even Muslim blacks. They just have a fetish.
- Pan-Africanism is a sensible movement and something whites should learn from. 
- Their literature and political thought are sometimes quite interesting, especially when it's black men lashing out against everything and being blackpilled (e.g., "Bigger Thomas" or early and middle Malcolm X). 
- Wacky movements and leaders like Marcus Garvey or the Nation of Islam are fun and allowed to speak their mind because of disadvantage Olympics.
- Black xenophobia and anti-Semitism are comical because they split the left. A lot of Ashkenazim need this antidote against the left-wing tradition in their communities.
- They're masters of blaming everyone else but themselves for their failures. It's so annoying in them that I think it's inspiring in personal terms not to be like that because it's sometimes tempting to behave this way.
- Blacks undermine statist flag waving because their activists are usually complaining about countries, while their statists are so over-the-top it's comical.
- Broadly, their history is pretty interesting, especially when stripped from tedious moralising drama.

As for black countries, I feel neutral, except in the sense that those people will be funneled into white countries, which I view with extreme negativity. I like some African history and don't think they're incapable of producing interesting or impressive stuff. I agree that the environment in Africa is very harsh and isolating from the rest of the world. Also I enjoy reading about non-state conflict, riots, and absurd cruelty because they're a curious window into humanity, and Africa delivers bigly. One of my favourite novels is "A Bend in the River" by Naipaul, and it captures the spirit of what I find captivating about it, a kind of perpetual spiraling towards the worst that you can easily predict but cannot prevent.

With individuals, I subscribe to the banality that there are good people anywhere that buck the trend, but it's only relevant for personal relationships. It's pointless to base policies, ideologies, or group assessments on this.