To follow up on my earlier comments, I discovered in my questions some of the tune providers that all the big auto providers are required by the government to certify the MPG and performance of a particular engine and transmission in a given vehicle. The Ford V-10 is installed in many more lighter weight vehicles like pickups so that is the vehicle they use to certify the V10, with some mods to reduce HP for really tight installations where heat is a factor. What works great in a pickup that weighs 7k doesn't always translate to a high profile billboard that weighs almost 2X as much. I am no expert on this but it is what my understanding is of the bigger picture. My E350 did a lot of downshifting, sometimes dropping two gears and then the engine is screaming into the 4k rpm's and it also shifted down at the smallest of inclines. I found it to be very irritating. My tune was not a five star tune but a Brazel Ultra Tune but I think all tuners are very similar and a great many people report that they are happy with both of them. Brazel is more expensive but then they also have a Dyno in their shop to test their tunes on. I have never priced a Dyno big enough to handle 40' diesel pushers but it can't be cheap. IMHO, what I think they are really doing is tuning your MH engine and transmission to match the vehicle you are driving instead an engine tranny combination that was tuned for the masses.
2001 HR Scepter 38 PBD, Roadmaster Chassis, 8.3 Cummins, 2013 Honda CRV with a Roadmaster Sterling tow bar and SMI brake system