After owning/driving (2) Class C's (2) truck campers, (1) class A, I can honestly say the 2014 E350 class C/B+ drives like RV sports car if there is such a thing.
I think it's more what coach you get and how it's built balanced that defines the handling, not the Chassis alone.
Example: I put the same truck camper on a SRW GMC 3500 and then on a DRW GMC 350 and they handled NIGHT & DAY from one another. Only difference. The weight and height on the SRW was not ideal, whereas on the dually it was perfect.
Same with coach builders. Where do they center the weight, the tanks, the aerodynamics etc. All are factored in on the handling.