As the headline says, I cannot judge the whole book’s quality, but I found the beginning so little convincing that I stopped reading and bought the book by Klose/Wrigley (which I can definitely recommend).
One reason for this were errors. There are some rather technical errors, for instance wrong URLs or a screenshot that shows a JSON response instead of XML (as the caption suggests), but also errors in the content. By this, I don’t only mean obvious things such as mixing up “solr.jar” and “start.jar”, but also issues like mentioning <defaultSearchField> or <defaultOperator>, which had been deprecated for months at the time the book was published.
The other and far serious reason was the structure. Why is there a chapter “Indexing with Local PDF Files” that starts with 15 pages that have nothing to do with indexing PDFs, but instead explains the structure of Solr? Why is there a headline “Posting example documents to the first Solr core“? in the very same chapter, which is followed by “First, we will cover how to write a generic, simple, and useful configuration“? Moreover, I didn’t get the feeling that things were necessarily explained in an order that made sense to me. (Which, of course, is my impression and other readers might judge this differently.)
Finally: When I visited the Packt Publishing website to take a look at the errata, I found that it listed errors that were reported in 2014 and were still in the e-book that I purchased and downloaded in early 2015. That’s pretty poor, and one more reason (besides the book’s content) why I don’t think I will buy another Packt book.