The quiets aren't good on small game. I had to shoot a rabbit 3 times in the head before it stopped flipping and flopping around.
The cci subsonic segmented HP on the other hand are just as silent as the quiets but devastating. Rabbit headshot with one of those anchored it without a twitch, and left its eyes about popped out of their sockets.
Are those the same as the CCI CB longs that sound like a pellet gun going off? If so, I've killed a truckload of squirrels, rabbits, groundhogs, and coons with them over the years. We used to call them "posted land shells " when I was a teenager.