Just another anecdote... with tire and suspension upgrades, I have no issues in wind or curves with my truck camper (9.2' floor, sleeping berth, 75"ceiling, 80" wide)...even though one of the suspension upgrades was removing the sway bar! It's also far better in wind while parked than I expected.
In the last 2 years I've twice driven the through the Salt River Canyon (steep and twisty) from Show Low to Globe, when fully loaded. No trouble exceeding the speed limit or keeping up with normal cars on the switchbacks. No one wanted to pass. I think it's ok. But it makes sense that a heavier duty truck will perform better in stock form... 1/2 tons are designed to ride decent for daily driving empty.