After letting my certifications slide, I figured it was time to re-up. I found this book an excellent resource. There are times when it came off as a mere listing of technologies with little "insight," but I know this is more a function of the exam than Lammle. He writes clear technical text, as good as most text books I've read. Better, he made me chuckle a few times along the way.
BTW, I am supplementing Lammle with Mike Meyers' Net+ text, and I find Lammle much better. IMHO, Meyers spends too much time trying to convince community college kids that his is a "cool uber-geek" who likes to overclock his PC. Lammle on the other hand is funny, but comes off as a wary, knowledgeable network tech who just wants to share knowledge.
That said, both texts do organize the information in distinct ways, so they complement each other. But Lammle's treatment is much more in-depth and less gimmicky than Meyers... which I, as an adult learner, appreciate.