I've read about a dozen servlet & JSP books, and I think this is the best one for readers with some prior experience in servlets & JSP. It is also an excellent book for people who are new to servlets & JSP, but I'll clarify that at the end of my review. The book is definitely worth 5 starts. The first star is for Marty Hall's clear and direct writing style. The second star is for being one of the few books that is currently up to date with the newest servlet & JSP specifications. The third star is for having very practical and useful content such as solid coverage of web application deployment. The fourth star is for being the first book that I've read that has detailed coverage of how to use SSL with servlets. The fifth star is for having source code, sample chapters, and a slew of prequel chapters freely available online.
If you read and enjoyed Mr. Hall's "Core Servlets & JSP", this book is well worth buying also. Be aware, the first 240 pages is an introduction which is essentially a reduced and updated form of the "Core" book. But the other 450 pages is all new and extremely good content. Even without the first 240 pages, the other 450 pages is worth the purchase price alone.
If you are brand new to Servlet & JSPs you may want to first buy "Core Servlets & JSPs" for a slower introduction to these topics. But, make sure you come back and buy this book because you will definitely want some of the updated and advanced topics such as "web applications." Alternatively, you can go ahead and buy this book and read some of the prequel chapters that Mr. Hall has online.
I haven't been fortunate enough to attend one myself, but I've also heard wonderful things about the onsite and public training servlet & JSP training classes that Mr. Hall offers.
In short, it's a great book. Enjoy!