fj12ryder wrote:
I've come up with another one: the gooseneck allows the trailer to sit lower and have a lower overall height.
Actually, a gooseneck can and does have a stronger frame. And that may mean taller frame section than a fiver. This is entirely because, unlike a fiver, there is no stand up living space above the gooseneck frame. There are many GN horse trailers with living area, BUT not above the gooseneck.
Fivers are constrained to 13.5 ft height and getting stand up space plus frame height plus clearance above the truck bed results in a minimal frame.
Build a gooseneck trailer with living area like a fiver and it will also have a weaker frame like a fiver. Build a fiver without stand up space above the truck bed and it COULD have a stronger frame.