My 2015 Silverado HD integrated controller seems to work OK, but I have it set at 10. As with non-integrated controllers I have had, the Chevy adjustment instructions say something like "increase the setting until the wheels lockup and then back it off". (I don't have the manual in front of me.) They also say if you can't get the wheels to lockup, leave it set on 10.
I would feel much better if I had been able to lockup the wheels and then decrease the setting. That way I would be sure that I have enough brake power for an emergency stop. (When I jam on the brakes doing 25, the rig stops reasonably quickly, but maybe not as quickly as other rigs I have had. Of course, this trailer is much heavier than others I have had.)