The difference is in the details. Many people will never know or care about what I notice.
I have had a Minden Fab trailer, an Avionics trailer, a trailer made by a trailer manufacturer that I never heard of, and now two Cobra trailers.
The Avionics seems to be an attempted knock-off of a
Cobra. It looks very similar. The construction, dollies, keepers, track system, and running gear look very close.
My experience says that Cobra pays GREAT attention to details. Especially nuts and bolts that do no protrude into the spaces that your hands will occupy when you begin to move things around in the trailer. I do all one man rigging so I am very intimate with my trailers.
Bottom line, I spent significant money to replace an Avionics trailer with a Cobra when the dollar was weak. The bolts that extended 1/4 to 1/2 inch beyond the nuts and would "catch" your hand or fingers got to be too much.
Avionics are well built but not refined.