In my mind the Super C's are like big trucks. They have basic truck parts and in a service situation they fit the truck. Most likely a Ford F550 chassis.
Now the Class A rigs.. they are a bit more unique. They give you a flat floorplan and put your front window right in the view when you are parked. Their front seats turn around and form part of the living room when you need it.
But they have their own parts, unlike just a Ford or a Chevvy Part.
So, buying new, if you can, go for the open format up front, but try to find a rig that others really like because you will want to change in the future.
Buying used, don't buy the oddball because it seems like a good deal. Get what others would want and get it early when it's for sale because someone else will want it.
good luck,
mike