Tire Ply 14 or 16?

I have a 32 foot Class A that has a gross weight of 18,000 lbs I need to replace the tires due to age, it has 14 ply tires on it now...I am thinking about going to a 16 ply tire with the new tires.

Has anyone done this, & if so what were your reason for doing this, also did it change the ride to a harder ride?