Think of how you will use the RV most of the time. There are always a few times when you wished for something else, but for the money you pay for a rig, your most of the time experiences are what count.
You will need to balance floorplan, room, and weight capacities. Newer Ford E450 chassis maximum load (GVWR) is 14500 pounds. From this, the weight of the RV "house" and all of its appliances, generators, slides, and gizmos are subtracted to give you the Occupant and Cargo Carrying Capacity (OCCC), i.e., the amount of stuff (food, clothes, water, games, tools) and people you can carry. In general, the longer the Class C, the less OCCC you have. Options like slides and automatic levelers reduce the OCCC you have. If buying new, look for the label on the inside of the RV that provides the OCCC. Don't count on the sales rep to provide accurate info on this. Remember, in a Class C it is not how much room you have, but how much weight you can carry.
Good Luck and Best Wishes on your search.