The only thing that matters going uphill is the total weight, either dolly+toad or tow bar+ toad. If the 4-down configuration weighs slightly less than the dolly + toad, then you are slightly better off.
Frankly though, I doubt if it makes much difference. The only real question is whether the Edge you want is heavier than the Freestyle. Probably not much difference there, either.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL