Its an interesting word in a modern view. Like so many words in english it can have more than one meaning and mean different things to different people.
I never use the word because as a white man I think its inappropriate and can be easily misinterpreted if overheard by a bystander.
The word is often used by some of my older black male friends as a term of endearment, such as "hey my N whats up"? When used like this its a compliment especially to a white man.
When white men use the word its almost always in disrespect and alcohol is usually involved.
Its almost the same as using the F word, it can be used in a nasty way or a happy way, the context is everything.