Yep, I've recently read a Packt book and I found I think at least a hundred (!) of typos, grammatical errors etc. These kind of things give very bad evidence about the publisher, and (not always justly) indirectly also about the author, even if he is very competent technically. Better avoid this kind of publisher.
I've read an HN thread a few months ago and there was a lot of folks, both readers and writers, complaining about Packt's quality.
I wrote a book for Packt (and later for O'Reilly -- much better!) and I still cringe when I think about people reading it. They gave me three months to write it, and it's been out for three years now, so code samples are slowly breaking as technology moves forward, and some of the content is badly out of date. The principles are good, and there are definitely some useful things in it, but, my god, what I wouldn't have given for a copy editor and someone to actually review the code. It was all written in MS Word, as well, which made formatting and editing a nightmare. Their editors actually put mistakes into the book. I think I took most of them out, but, like I said, their deadlines are nuts.
I've read an HN thread a few months ago and there was a lot of folks, both readers and writers, complaining about Packt's quality.