I can't speak about the the new V8 that has just been put into the newest Class Cs.I have not seen many posts on them,what I have seen is that they are much quieter than the V10 under load and seem to be de tuned some for better fuel mileage.
I can however speak about a Class C V8 on
Chevy Chassis.
I have a friend that has a V10 in his and we go all the same places and we seem to have about the same performance except I get a bit better fuel mileage and am not as worn out as he is after a long run fighting an ill handling rig even after all the time,money and work he put into his,following all the tips that have been brought up here on the Forum.