As a former Newmar owner, you may have some experience with diesel coaches. Based on your experience, don't fear any of the MB Sprinter based C class motorhomes. I have a Winnebago Navion, sitting on the 2017 NCV3 Sprinter chassis, and it's been pretty flawless to date. I was hesitant to go diesel after a couple of gas adventures, but soon realized I should have done it sooner. The power and fuel economy, being two of the pros, as I learned about diesel engines over the last 5 years. They have cons, but not enough to make me go back, with one exception. The Winnebago EKKO, is a 4 season class C motorhome that has "off grid" technology incorporated into it's coach and chassis systems. Too bad they're so **** expensive, or I might have one. They have the Ford V6 Eco-Boost gas engine, but the power and torque specs are "diesel" in nature. And, they're AWD which would be nice in certain road conditions.
Mike. Comments are anecdotal or personal opinions, and worth what you paid for them.
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 Wrangler JKU (sold @ ????)
2016 Sunstar 26HE, V10, 3V, 6 Speed (sold @ 4600 miles)
2002 Roadtrek C190P (sold @ 315,000kms)