Disclaimer: The author sent me a review copy.
Even without the review copy though, really, my opinion wouldn't change. Wisconsin's Best Beer Guide is the most essential beer-and-travel guide for the State of Wisconsin. Period. If you don't own it, you should. It's been updated recently and contains all of the latest breweries in the state as of 1/1/2013.
Show the book at any brewery in the book and get a free beer. It'll pay for itself after about 3 breweries. Heck, you probably don't even have to leave your town/city to get your money's worth.
But, it's best use, for me at least, is as a handy companion for when you find yourself traveling and have some time to kill. Go up to Ashland to meet your family for the weekend? Pull out the guide and find out all of the breweries in the region. Find yourself in La Crosse for business conference and want to grab a beer with some new-found acquaintances? Pull out the guide and be the hero. Trying to go to every brewery in the greater Dane County area? This is the definitive list.
It's about the best $12 you'll spend on beer in Wisconsin.
Hint: If you're looking for a last-minute Valentine's Gift what better way to say "I Love You", than "Here's a whole book of free beer"?