>>666923whynotboth.jpg
There are some skeptics on the "bear spray is superior" claims that the government and some biologists seem to push (and some people suspect they have an agenda). A lot of those early claims were lacking facts to back them up, especially the nonsensical claim that "50% of all bear encounters with a firearm involve the gun owner being harmed" and yet no facts ever emerged to back that up.
http://www.examiner.com/article/bear-spray-vs-guns-argument-is-ridiculous-says-bear-safety-expertDepending on the circumstances I would happily use a non-lethal deterrent first. A bear on the trail in front of you that is not charging doesn't need to be shot obviously. If it is not a windy day the spray should probably do it's job and drive away the bear. The gun should be ready as a fallback though, and the gun owner should be well trained in it's use. Shot placement is very important.
Pic related was a world record Grizzly killed by a .22 at close range. The bear was almost right on top of her she she shot it.