Good reasons for a small Class C:
1. You have one!
2. In between an EXPENSIVE travel van and something larger.
3. All the "comforts" but in a smaller footprint. (Like a laptop instead of a desktop but larger than a netbook.)
4. Shorter overhang (usually)--makes more backcountry access possible.
5. Good for togetherness.
Good reasons NOT to have a small C.
1. Too much togetherness.
2. Limited storage--limited clutter control.
3. Too much physical flexibility required.
4. No need for backcountry access.
5. You don't have one!