The features of the Allison tranny are great in finding the right gear, especially for someone that does not understand gearing. But it can do nothing more than any good driver can do that knows how to use his gears. It does not increase braking horsepower - - that takes an exhaust brake. I can't answer for the Chev, but on a Cummins, braking horsepower is increased about 100 hp with the EB. That normally means being able to run in one higher gear than without one. On some downgrades that can be a great advantage.
2003 Dodge HO 6 speed Laramie Dually, Jordan controller, RDS fuel tank, Air Ride 25K hitch
Carriage 36' fiver, Onan 6500, Prosine 2K inverter, 3 slides, MORyde IS and Kingpin