Brown bears are violently territorial and will attack you for being in eyeshot.
Black bears are basically giant racoons and will move away from people - especially if you're making loud noises and making yourself look big - because they don't want that smoke. They'll only get aggressive if you surprise them or get anywhere near their younglings.
I'd probably take a black bear over a lot of dudes. As long as we got a good hundred feet or so of distance, Mr Bear and I ain't gonna bother each other.