Meh? White missionary man goes to hang out with those primitive brown people in the jungle and learns a lesson and has wacky hijinks along the way! At least for part of the book... I guess if you are into linguistics, this book would be better. But I'm not.
The first part of the book was largely short stories about the author's life with the Piraha, their attitudes, customs, lives. And if it had ended there, I probably would have liked it a whole lot better.
The middle part of the book was all about linguistics, grammar and culture. I liked some of the discussion he had about the effect of culture on grammar (the easy part), but when he got more technical and was talking deeper about theories with grammar and linguistics, I think my eyes glazed over.
At the end, he briefly mentions his conversion to atheism (he originally went to the Piraha as a missionary, primarily to learn their language and translate the Bible), which might have been more interesting if he fleshed out descriptions or explanations of what led to his de-conversion and more about the fallout (both internal and external) that it had in his life.
The writing is not great (or just plain crap). On top of that, some of the descriptions are inconsistent (Everett repeatedly refers to how peaceful the Piraha are, and then mentions violent acts they commit, like a gang rape; he mentions that they don't have a word for "sorry" and then turns around and translates something as "sorry").
I don't know, the book was uneven at best and mind-numbingly boring at worst, but it wasn't terrible or anything. I'm not sure what the point the author was trying to make was. If he wanted to just tell a story, the entire linguistics section needed to be removed or pared down by quite a bit. If this was about the linguistics, maybe it needed a better title.