Motorhomes on Mercedes Chassis

I had a sprinter, the RV was good, Mercedes diesel with their “4-metic” tranny. Depends on where you go for maintenance, of course a Mercedes dealer is very expensive, as all dealer shops. One problem, not all Mercedes dealers would handle them, so finding warranty shop was difficult. The other problem, I thought it could have used a larger fuel tank, or an auxiliary tank. Mercedes would void your warranty if you did anything but fill the tank. The reason I got rid of it was the Conner bed. Nothing to do with the chassis but I thought I would mention it.