My '03 Dodge/Cummins 5.9/NV5600 six speed manual tranny has the Jacobs exhaust brake. The '03 was the first year of the new HPCR engines with the 4" exhaust. Jacobs was late with the new exhaust brakes.
Towed a 11k 5th wheel trailer and other GN flatbeds for 3 months before the EB was ready and supplied to the Dodge dealers. Downhills was scary as zero engine braking. Just like shifting the tranny to neutral.
After the Jacobs was installed I used the trucks brakes very little (135k miles before new brake pads/front only).
I wouldn't own any brand of diesel without some type of exhaust braking.
Some folks bought a EB and just installed it. No braking..... Gotta' install all the necessary engine/tranny software and hardware to make it work right so check with the exhaust brake mfg as they can tell you what is needed for your particular vehicle to make the EB work like it should.
