I have over 200000 miles on two 7.3 with exhaust brakes. Mine are (were) a 96 and currently a 99 both with manual transmissions. The 99 has the original brakes on it, with loads over the 20000# GVW and lots of mountain driving. I’m presently replacing the uppipes, which could be due to exhaust brake use or a lacking design. On a steep grade, it really helps with any load. With an auto, you’ll need tuning or something like a Banks TransCommand to hold lockup in the transmission.