I work as a web developer and I use this set all the time. I can take it with me to help other developers and/or read it while away from my computer. It is very easy to locate what I need and allows me to find what I'm looking for when I don't quite know exactly what I'm looking for. It's not the end all to Perl references but it is the best hardcopy out there so far!
I use this set every day of my life !!
I must be honest, I'm writing this review mostly to netralize the bad reviews thus far.
That this book is on a CD only begins to demonstrate the effectiveness of it's contents, but this IS indeed an important feature.
I only wish this came out sooner (or I bought it sooner), when I was web-designing free-lance a couple of years ago.