I can't help on the "medium-duty" part, but my Barth motorhome has HydroBoost hydraulics, and discs at all four corners. The rear axle is a Dana 80, and the hub has to come off to remove the rotors, which is a double pain because I have wet rear bearings.

One thing many med-duty trucks have is stud-piloted wheels, where the studs take the load, as opposed to hub-piloted, where the hub takes the load. The front brakes are easier, since they're on a dry (grease lubricated bearings) hub.

Brakes are Dayco all around.