Guys... chill, if I've bought this companion I've already decided to read this translation, you don't have to keep selling me on it. The tone of these essays is a little too insistent. That said, I bought this really for the glossaries, and the historical overview is good. More historical articles would've been better, and more info on Sienkiewicz as a person (we only learn his opinions on translation and royalties) would have been good too. It was worth the few bucks I found it for, but really it depends on how badly you want glossaries on hand when you read The Trilogy.
It is a handsome edition, but in the end it kinda feels like info that should've gone into the books themselves padded out, kinda, with advertisements. Ah well.