I have had some experience with very bad Memphis brand guitars as well as some VERY GOOD ones that were obviously made with quality in mind.
I owned one that was an exact copy of an Ibanez "Custom Agent" with a setneck, F5 style headstock and mother of pearl inlays on the body as well as banjo style inlays on the neck. The guitar was absolutely gorgeous and a great player. It sold for $750.00 around 8 years ago. I was sorry later as usual.
Another good one I owned was a Les Paul Custom copy with the open book headstock, setneck, multi-layered binding, real mother of pearl sail inlays on the headstock as well as mother of pearl block inlays on the fretboard and factory Gotoh tuners that were identicle to the "Star" tuners Ibanez was using in the 70's. It weighed 9 lbs and the neck was very straight with nice low action and no buzzes. That one sold at a guitar show 10 years ago for $600.00. It didn't last more than 3 hrs.
I have also seen the other extreme where the guitars were absolute low budget garbage and I was upset at paying $150.00 for it when I got it. I guess it depends on the model year and where it was made.
I would not be surprised to find out these guitars were manufactured at many different plants at different times due to economics and marketing. One thing for sure, Don't judge that open book by the name....each guitar needs to be examined based on it's own merits regardless of what's on the headstock.
Bob