Well I took my truck out and measured the performance of my exhaust brake today. According to what I measured it appears to be no better than, and probably worse than was the EB on my 2017. The 2017 would slow my truck from 100 kph to 80 kph in 4 seconds .... this one took 4.8 seconds. I guess the Ford is both faster up the mountain as well as down when compared to the Ram.
Edit: I measured its performance in 5th gear with the engine revving between about 3100 and 2600 rpm, so, although its not impressive with the engine at that rpm it will probably be much more impressive in 4th gear at 100 kph and 3600 rpm, or for extremely steep grades 3rd, 90 kph and 4000 rpm.