Like Walt, I live in some pretty serious bear country here just north of Yellowstone, and its only getting worse (or better, depending on your viewpoint). I don't think anyone can really say how they will react to a grizzly charge. It's fast, and it's scary. Suffice to say, you try and stop it before it gets to you somehow, and then if that fails, you resign yourself to killing the bear or deterring it's aggression before it kills or seriously hurts you first.
I carry both nowdays...a Glock 10mm on a chest holster and spray. 10 years ago, I was more inclined to carry just spray, but these days, less so. I guess my thinking is like Walt and Kevin's...I like the deterent of the first shot and the multiple follow ups if needed.
If you are going to hunt bear country, there is nothing like understanding why bears will attack or charge, and anticipating the situations you are getting yourself into before it happens. As bowhunters, we study our quarry and it's environment, and this is no different. I've spent my whole life hunting and recreating this area here, as well as one trip to Alaska...and haven't had a bad bear experience yet - knock on wood - but I know what to expect and I have no preconceived notions about what can happen. Every year we have numerous bear/human encounters in the area, and it's always sobering, but it's also a testament to the health of the natural world around us, and part of why it's as special a place as it is. Only Alaska and Canada can rival this area.
After all the bear hysteria, I have to say, I still worry more about big cats than bears...something AK does not have! And I have had experiences with them....and I know Walt has too! Just ask him....