Wayne
My experience is all positive. My C12 powered coach has been mine since 2006. It has been reliable and eager with every turn of the key. Mechanical issues with engine have been ZERO. You need to pay attention to the engine braking difference larger diesels have over smaller ones. In the highest stage the C12 engine brake is large. MPG info will only be useful if we are talking identical units. Mine only weight about 25K and returns in the mid nine's effortlessly. If I drove 55 it will return an honest 10-10.5 all day long.
Maybe you should share what coach you are looking at and let others weigh in on other aspects that are important also.
