I have never seen one myself but I'm convinced that a grizzly encounter is like being in the path of the tornado.....
They are incredible animals. When you see them just lying around, they can seem kind of clumsy and rolly polly. But when they run....it is just shear raw power and muscle.
Some years ago I shot a brown bear on Kodiak (a sport hunt, not a defense shooting). It was a great adventure, but these days I find I really enjoy just watching them.....with my binoculars from an appropriate distance. On my most recent trip to Denali National Park , a week ago, we were priviledged to see several groups of bears, doing their bear thing.
I would urge people to check out the link to the article on the effectiveness of bear spray. It makes for intersting reading. Here it is again:
http://www.alaskadispatch.com/sites/default/files/Bear%20Spray.pdf Even though, as noted above, I am quite handy with firearms, these days my personal choice is generally to only carry spray when I am out hiking.