At risk of goiing OT:
Geo is right, a charging bear moves vertically about a foot. It is something to behold when you are on the wrong end
The main issue I have with kneeling is that you have to change your position from standing to kneeling. When you only have precious few seconds to react and shoot a charging bear why would you waste any of that time kneeling instead of shooting? Also if you kneel you are less mobile and unable to move if needed as it closes in.
That's just my opinion, yours may vary and I am not saying mine is better or worse.
A good test of the difference in response time to a charge is to start with rifle/shotgun in field carry position (rounds in mag but not in chamber) start position is standing at low ready. On the start signal (Start of target charging) fire as many rounds into target as you can before it gets to you. The time it takes to kneel is time lost shooting. I'll have to try both ways just to see what difference it does make.
Cheers
Now back to our regularly scheduled programming.....