At work, one of our fleet trucks is based on the w22 frame. Its a cargo conversion essentially, but its terrible. The electrical issues alone have made this truck no longer viable. It is grounded for local use only. We have had it have it towed 3 times already for various issues. The engine has been rebuilt once already, I believe due to piston rings causing lost compression. The allison transmission is great, amazing even from what im told, however, when its onboard computer decides its not receiving enough output from the engine, it de-rates and then you lose both overdrive gears. 50mph max, to the floor, at 2500rpm. Forget fuel economy then.
When I got the bill for the electrical repair. I just about hit the roof. $6000 of labour to track down the electrical issues causing the transmission to stay in park despite being shifted into gear.
Turns out that the main pigtail harness ended up flexing and breaking a number of the interior wires.
Its crap. Workhorse is/was crap. Of course, a motor home is not a cargo truck. Its a more complex, delicate, and expensive piece of equipment.
Sorry. Just my 2cents.