From what I understand the headstock open book design is how a "lawsuit" Ibanez is identified. I bought a 1975-76 Ibanez Deluxe 59'er at a yard sale last year, I am very pleased with it. I actually like it better than the Gibson LP I owned years ago.
I have a "late 70's" Ibanez mandolin that is a "Lawsuit" instrument. Ibanez dc'd them for nearly 30 years and only recently resumed production, although at a lower level of quality woods. My mando sounds excellent and is very playable and from what I've seen of the comparable Gibsons, and the new offshore products, was a steal at $300.
i play an agile les paul, and when people ask me i usually say its a knock off les paul by a great company called agile by rondo music, sorta like the old lawsuit guitars, really high quality stuff.
but really im just trying harder to impress them because if its not a gibson then the idiot kids im usually talking to dont know any better. then they see the finish and play it and hear the tone and forget all about the name on the headstock
i agree with the OP though, more than half the time its just a bullshit tag stuck on there to sell it faster on ebay.
really though, agile is making some damn fine guitars with a qualityrice ratio that puts atleast epiphone to shame, maybe some gibsons aswell.