Downshift or exhaust brake?

I live in very hilly (mountainous) country; Idaho. I use my exhaust brake all the time and it really does help alot in cutting down how much I need to hit the brakes going down hills. I also keep tow mode activated all the time. With tow mode on, exhaust brake on, and starting at the top of the hill at a reasonable speed, I almost never have to hit the brakes all the way down. I had a gas truck (Chevy 1500) years ago with a relatively light, Jayco Jay Feather trailer. Coming down the hill from Anthony Lakes, Oregon was a VERY scary experience. I had to keep hitting the brakes. By the time I got half way down that hill, I was certain I was going to burn up my brakes. They sure smelled that way! I have since gone down that same hill with my F350 diesel and 14k fifth wheel, and I coast almost the whole way (with tow mode on and exhaust brake activated).