When I was looking for a trailer, I looked at Benderups. Had a mechanic friend go look under one for me and his words were to the effect of "You couldn't pay me to tow that out of this parking lot unloaded".
They are riveted, welded and all in the wrong places. Put a horse in there, drive down a highway and get a gust of wind and I don't know if the welds would hold up because there is not a bolt in the thing and where a "real" trailer has straight, untouched steel, these things are 1' pieces of aluminum welded together. Scary, scary, scary.
I would not recommend one to my worst enemy.