The only advantage with a tow dolly is that you can tow multiple cars by just driving one of them onto the dolly. The loading and strapping it down time is much longer than towing four down. Storing the dolly when you get to the campground is another thing to deal with. Maintanance on the dolly is yet another issue to deal with. If you will tow one or possibly two vehicles only then you may want to think about towing four down. Good luck and keep us posted.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7