I would say it depends on the "B". ProMasters have a telescoping, but not tilting steering wheel, so they tend to drive more like traditional vans. Sprinters and Transits are more adjustable, and tend to be more car-like.
Rides can differ greatly among class "C"s as well. Some have airbags, others vary from good road manners to white-knuckled driving.
If I were to recommend a class "C" for road manners, I'd recommend Coach House, Phoenix Cruiser, Or Lazy Days. If I were to recommend a class "B", I would probably recommend a Transit, although a 4x4 Sprinter is nice as well.