I’ve been running ProGrips for almost a year now, I am very pleased with the braking power. I am on 37s for 3 years now, with ProGrips for a year almost, I am finally comfortable with going down the obstacles knowing my Jeep will actually stop when I need it to. Brake pedal feels nice and firm with ProGrips, just like from factory.
If you are upgrading calipers to a double piston ,you should also upgrade your brake booster and brake lines, and after all that work your brake pedal will feel mushy. I don’t know that form experience, it’s the information I found during my research prior to upgrading the brakes.