Not having an exhaust brake would be a huge mistake. I wouldn't own a diesel that didn't have one.
That said, I want the ability to turn it on/off as needed.
"With a torque rating in the mid-500s (lb-ft) and more than 300 horsepower, the Cummins 5.0L V8 Turbo Diesel will provide light truck customers the combination of towing capacity and mileage that is expected in the highly-competitive North American truck marketplace."