I'm an ex RV'er , A. fuel economy is all they ever talk about, then they buy a class a diesel , run an onboard generator for weeks, tow 2,200lb SUV's and leave them idling for hours when out for a hike to keep the A/C up. LOL
the challenge with those dolly setups are 'trailer tires and bearings' which are just another link in the chain to deal with as opposed to 4 wheels down. But so many vehicles are different and how you tow a JK wrangler, Civic and F150 are all a bit unique. Especially when your going 6,000kms.
best sport ever is watching somebody that isn't a retired transport driver or farmer (4wheel hay wagons) try and backup once they get into a tight space. super short wheelbase hitch, terrible visibilty and zereo chance of success.