For the price of them (usually less than 8 pounds) I have only ever passed on ones that cover periods I have zero interest in. And of the ones I have bought more hits than misses (OGAM, IHMN, Gaslands, Zona Alfa, Black Ops, En Garde, TMWWBK, Lion Rampant, Fistful of King Fu) , even if I've never actually played them they have been interesting reads full of good ideas.
I will probably pick this up.