The good: this book is surprisingly candid and revealing about the nature of the players in the league, in a way most of these types of books aren't. Usually ,the reporter gains access by promising to mythologize the players and whitewash the really negative sides of life in the league. Gargano sometimes seems to not quite get that most of the stuff the players are saying is kind of awful, and that, at best, most of these guys come across as complete idiots (not to mention sociopaths and homophobes). But still-- the book reveals this side of the players that the NFL is usually trying to hide, and so it succeeds in one of its main goals.
The bad: The prose is sometimes comically overwritten, to the point that it's not even clear exactly what he's trying to say (ie- "The back-in-the-day guys who sport their scars and crooked fingers and clicking bones like stickers of buckeye tree leaves on the Ohio State helmet would prefer to deem the current shift in the game permutation instead of, say, evolution, because of the connation, you know?" He really, really overuses "you know" in the book too). Another example: "They called him Zeus, and how fitting the nickname. You could envision him standing, striding forward, a thunderbolt leveled in his raised right hand. Mighty Zeus, ruler of the sky." It's a bad Bill Lyon impression, really. Even the dumbly inflated language of calling Peter King "the extraordinary football scribe" is a bit off-putting.
The book is at its worst when it tries to make connections between the game and Big Real Life Things, like comparing the line of scrimmage to the border fence between India and Pakistan, or like in this muddled line: "And basketball's expansion is reminiscient of the Roman Empire in its latter days, when global domination matterd more than life inside the kingdom." That kind of stuff is just ridiculous, and it's problematic because, as much as he says it doesn't make sense to compare football to war, he does it constantly.
The book needs an editor. I'm not one to harp on typos in books, but the number of copyediting errors in here is embarrassing.
Finally-- the organizational structure is totally incomprehensible, and leads to frequent redundancy. I mean, it's a total mess, and there's no logic behind the placement of anything, particularly beyond chapter 2, at which point he abandons his planned structure and just starts padding things out.
This is a really negative review, I guess. It's an interesting book for behind the scenes stuff on football, and getting a mostly unvarnished view of the players. It's not well-written at all, though.