Towing a vehicle 4 wheels down (also referred to as "dinghy towing" or "toading") has many advantages and is becoming more and more popular. Perhaps it's because this method of towing has little or no effect on the handling, gas mileage, or overall wear of your coach. Plus, it gives you the freedom to go sightseeing, shopping, or exploring on a whim.
On the other hand, to tow your vehicle 4 wheels up, you'd have to purchase a trailer, and towing 2 wheels up comes with its own share of inconveniences from using a tow dolly.