We pull our 5th wheel with a Ford F350 truck. It gets the job done, for sure. Problem is that once you are parked, that is definately overkill for doing your daily errands, getting to work, etc. I have met people who also take a motorcycle or moped along to use for this purpose, which is an option.
We chose the large diesel truck because our 5th wheel weighs about 14,000 lbs and we often travel cross country, sometimes over mountains etc,and we would not ever encounter a situation where we would not have enough towing capacity. Fuel mileage is HORRIBLE to say the least but is just the cost of doing business, I guess.