Last fall we bought a Phoenix Cruiser 2350 with the Ford 350 chassis. We looked extensively for two years and really liked the MB chassis but declined to buy one because of availablity of service.
In a New Mexico campground last summer I met a guy who had the MB chassis on his unit. He told me he broke down once in western Kansas and had to be hauled back to Kansas City (well over 200 miles) for repairs. I looked at the MB webpage and the map of the service centers. In the Southwest, one in Albuquerque, one in Denver, one in Kansas City.
Where I live (Oklahoma) we have two in the state: one in Oklahoma City and one in Tulsa. Both are Freightliner places. Something told me I would be low man on the totem pole with my RV at Freightliner when they have service contracts with fleets and they are full of cross country rigs for service.
Chevy or Ford? Less than five miles from my house and in practically every county seat in the US. So, good old Ford it was for us. Not many B+ units have the Chevy available. I have owned both in the past and find both very durable, serviceable and sufficient for our needs.
PSW
2013 Phoenix Cruiser 2350