IF the car can be towed 4 down there are many advantages to doing so.
If you do it properly you only add around 100-150 pounds to the car/Motor home for the tow gear (including braking system)
The aux brake system brakes on ALL wheels thus shortening your panic stop distance (Dolly can only brake with the dolly wheels, NOT the car's so you have increased stopping distance.
Dolly is harder to climb up on than modern telescoping tow bars are to hook up
Added weight to tow (may exceed Gasser limits) and big thing to stow when you park.
This is why I tow 4 down
I have towed with dollies, and trailers.. but 4 down is way easier.