Guns aren't much of an option around these parts, but I don't feel ill-prepared with just bear spray as a last line of defence.

The only study I've heard referenced found bear spray was effective at stopping aggressive bear behaviour in 92 percent of case while firearms were effective in 67 percent of the cases. This was study of 20 years worth of bear encounters in Alaska.

This same study also suggested wind wasn't as big of a factor in bear spray's effectiveness as commonly thought. Also, interestingly, it found the hissing sound and visible cloud are in themselves an added deterrent (from this article).