Almost three and a half years later you're finally getting around to this!? 
Over the years I've lost count of the number of languages I've programmed in however one constant has been that no one resource is adequate and it was not unusual for me to have several if not more books on any given language that I was programing in. Different authors have there own style and some cover different aspects of the language more then others etc. and much can be learned by using multiple resources.
There are plenty of publishers that provide a sample look at the contents of a book for one to see if they like the style and feel it might be more conducive to ones own learning then another book may be.
Drewdin seems to have found a particularly good one.
That's a subjective statement at best! Your OP and initial replies were on Oct 18, 2010 and at that time PHP was at the 5.3.x release and the current stable release is 5.5.9 (and the 5.6.0alpha2 was released a week ago). There have been changes both additions to and removal of functions between those releases and obviously the book Drewdin read was on PHP 5.3 or earlier and as such I would opt to read a book based on the most current stable release version PHP 5.5 if I was just starting to learn PHP. So IMO it's somewhat irrelevant what Drewdin read almost three and a half years ago.
It is much more productive to model other people's successes.
While that might be considered a nice axiom nonetheless IMO it is not necessarily applicable to everything. Now if Drewdin was the author of the book, well I might look at it differently!
BTW He hasn't posted anything in almost three years, so he may not even be getting notifications anymore.