Multiple vehicles may be towed, 4 down one vehicle only.
Changing toads with a dolly tow will likely be free! New 4 down toad results in removal from the old toad and installation of the gear in the new toad and maybe buying a new base plate. Likely a tidy sum!
I doubt there is much difference in the hock up time.
As noted previously, the "investment" for 4 down far exceeds that of a dolly and that "investment" is unique to the specific toad.
The hew and cry about where to put it is a red hearing. Role it under the back bumper and carry on. There is not a lot of activity taking place at the rear end of the coach!
Bottom line, each method has both pros and cons. The upshot is that the OP is the person who will be using the equipment and therefore that equipment must be tailored to that person's specific needs. There is no right of wrong!