I found this book very worthwhile and pitched at the right level for me (an experienced programmer who's just getting into JSPs/servlets etc). The book progresses through the subject material at a good pace, with little extraneous detail - you seem to get a very good dose of valuable information from every section. Some people may find it a little terse but, as I havent got time to read waffle (!), I found the style direct and accessible. The book acknowledges the foundations of JSP, and so contains useful detail regarding servlets rather than concentrating wholely on JSP. I did notice a fair few grammatical errors, but it gets the important things right. Overall, a very handy read.
Too many cooks spoil the broth and in this case too many authors has resulted in a book that's repetitive and disjointed. It includes dozens of pages of auto generated servlet code which seems to serve no other purpose than to make the book fatter. You'll find that the accompanying code is missing segments and you'll loose count of the number of typographical errors in the book. Try "Core Servlets" instead. This book gets 1 star as it may be useful as a reference but that's about it.
If you have purchased any of Wrox publications before you won't be too surprised at this one. It is extremely comprehensive and well laid out. The only problem I have is that it is probably too advanced for your average programmer. The people who write these books are extremely intelligent, and write very concise code - may be too concise for the average Joe. Some of the examples given are also confusing. But generally you won't be dissapointed.
This is a good book to a Java programmer wishing to get started with JSP and other related technologies. But there are so many typographical errors that at times a reader will only be more confused. It could easily get a 4-5 stars rating if not for this serious flaw.