I am going to have check myself here.
I have a knock off Epiphone LP. It was made in the same Chinese factory that manufactures the same guitar for Gibson. It is made out of the same stock of wood, it uses the same Gibson/Epiphone parts, it is made on the same CNC machines that make the Epiphone LP for Gibson, and used the same blueprints that Gibson provided for their product.
In short, though a knock off, it is the identical product, but at 1/8th the cost. How is it inferior.
On the other hand, I have another guitar that was made in the same factory prior to Gibson and PRS buying out the production capabilities for that factory. In every way it is super to the Gibsons and PRS's. It uses AAA woods, top notch pickups and controls, real mother of pearl inlays (Gibson and PRS use phenolic acrylic), looks like a cross between an LP and a Telecaster, and so on. The guitar cost about $200 with a hard shell case.
It all depends on who and what you deal with. Copyright/trademark/patent after a few years does nothing more than to protect a companies right to scam you for the most dollars for the longest time. After all, guitar technology has not markedly improved since the 1950's.