I have and do use the word, i'd be lying if i said it hasnt slipped out, but its just a habbit i picked up at a early age, Too me it shouldn't be used. And i stopped using it in my music a long time ago, if your hear it in my raps, its an old ass song. we all know when you say it, it aint on no racist shit. and when you say "thats my nigga" To me thats like the mafia saying "this is a friend of ours" that means you and that dude got a strong history together, thats how i kinda see it. but you know shit is just a slang word nowadays to most people.
I work with alot of black homies that i've grown a strong friendship with. So out of respect i stopped using the word, nobodies ever checked me or no dumb shit like that, but there been times when we've caught a few looks. So i guess it does offend people. If you've ever sat down and had a conversation with an old black man or woman, you'll know that shit is highly offensive and you should know your place.