I didn't realize there was some super-special configuration needed. I don't follow the pro-gaming stuff so I don't see what the point in using a low sensitivity are.
In my case, I lower it if I'm in an area where some precise sniping is required and I know I'm going to put my character in a static position either crouched or prone. Even at that, I never had any problems doing that with my G5 and I most certainly am not having any problems with my new G9.