I run an IBI 3 Gill brake on my 6.5CM and it works very well but like a lot of brakes, it is quite loud and unpleasant for people shooting to the side of it.
When we all go out with our long guns, I usually try to pick the end lane (or be on the end spot, if we're out in the bush) so I don't annoy people. It definitely was blowing dust and debris from my lane to the others last range trip.
The PRS .22lr guys at the range look at me like some sort of uncivilized swine lol