It's funny, when I first mounted the holosight on my GS, I got some funny looks at the range, this being quite some time ago. Today, I have quite a few asking how it works, what brand, etc. For once I was on the cutting edge of something.
As to the sling throwing off once balance, when moving from target to target, I can't say. I've never had to engage more than one animal at a time.
Someone mentione North Hollywood. As I watched it unfold from the safety of my living room, I was thinking of another incident where the cops were outgunned. That was the shooting from the "tower" in Austin. Reportedly, some citizens tried to employ their own rifles, but couldn't get an angle on the shooter to obtain any hits. I do wonder what would have happen in North Hollywood had a single armed citizen employed a lowly scoped bolt gun in say 30-06.
Though most likely, had someone engaged and neutralized the bank robbers, they would have been arrested, tried, convicted and would still be in jail.