Here's the first review of the book that I've found, from Pendragon's Posts:
He gives it three out of three Yo Joes! "Nothing like reliving the eighties style of cartoons with some files cards thrown in the mix." Sounds like so far I'm one for one!
Here's a nice unboxing. 1:36 in or so he gets to the Field Manual and has some very nice things to say.
G.I. JoeVersity posted some rather kind thoughts on the book. Here's an excerpt: "It’s a fantastic resource for fans of the toys, the cartoon series, and the comics. It’s wonderfully laid out, and contains just about every design and character sheet for the first season and a half of A Real American Hero."
Amazon.com has a couple of five-star reviews! Some quotes include these gems: "I'll add that this works very well as a 'how to draw G.I. Joe' book - and if I'd had it in the mid-eighties I probably would never have left my little drawing table!" and "The 'G.I. Joe Field Manual' is an absolute joy. It is a behind-the-scenes visual delight of Season 1 (and the pre-Season 1 mini-series) of the 80's G.I. Joe cartoon by Sunbow, and a wish come true for G.I. Joe collectors (especially 'Joe cartoon fans), or even fans of cartoon "bibles" in general."
Look to The Lottery Party for another in-depth review. "Tons of interesting research from the two authors, and I look forward to checking out volume two." Thanks, guys!