I still believe that there is value in the newer of the two Noonan books. Sure, the book is a bit dated, but there is absolutely no other affordable brewing text that is dedicated to brewing traditional lager beer. That being said, I would look at purchasing the book used. I purchased an original version of the book in mint condition for not much more than the cost of shipping. That is the version I had in my library before I sold off my entire brewing collection. Noonan is the only publication that is written in English that covers a decoction mash in gory detail. Granted, decoction mashing is not as necessary today as it once was, but there is still value in learning the technique. Even with modern malt, I find that decoction mashing produces a different wort than infusion or step mashing.
Agreed. Despite the extent it might be dated it is still the most technical homebrewing book out there. There is a lot to take away from the book even if you don't brew lagers.
Brewing Better Beer is a really good intermediary skill book.
Brew Like a Monk remains an exceptional guide to trappist/abbey beers. All of the white books are good but BLAM is the best of the group.
American Sour Beers is a good guide to getting into sour beers. Wild Brews is a great guide to classic Belgian styles and also worth reading.
The Homebrewer's Almanac is a great guide to incorporating unusual plant ingredients in beer. Brewing Local is a pretty good second in that subject.
IPA is a good guide to IPA before the domination of haze.
The 1990s Brewer's Publication style books are full of awful misinformation but great snapshots of craft beer in the 1990s.