I've used them in years past. I like them because I can plan on seeing the shops ahead of time instead of trying to look up shops in the phone book. I use them as reference too.
However, the phone book will also list shops that are not in the quilters book. If it were up to me, I'd make it mandatory that all quilt shops be listed in one book that we all could get.
But then half the fun is discovering some of these hidden gems off the beaten path.