Zebrafive
Super Member
One thing that you have to put up with the whole time of ownership is engine noise! Quieter engines are normally from a better smoother working design.
My recommendation would be to listen to both at the same time, if not possible at least at two different times and you should hear the difference. I'd be taking the 6000 series because of that reason on it's own!
Have listened to both models? Since both have the same size engine and are turboed, seems to me the better cab would make the difference.
I'd pick the one I liked the cab best.