I have a 2005 Itasca Class C that I bought new in early 2006. The Ford E450 chassis under it was built in late 2004
I have the 5-speed (6 speeds internally) Torqshift transmission with Tow/Haul mode and it has been fantastic. This transmission applies the brakes automatically going downhill whenever you're in Tow/Haul mode and applies the brakes automatically going downhill whenever the cruise control is ON so as to not exceed your set speed - whether in Tow/Haul mode or not. Cruise control can be used out of Tow/Haul mode or in Tow/Haul mode.
It's an amazing transmission teamed up with the V10 - definitely get a late enough RV model to have this combination.