"Keystone Fly Fishing" - soon to be released - takes a different tact on the guide book genre. Here the state is broken up into regional sections (that's been done before), & has a different author & local fly fishing expert write about each region (a new approach). That, to me, sounds like a good approach. Pennsylvania is too big, with too many streams, for any one angler / author to know it all. This book promises to give much more detail about the smaller, less known trout streams. It leads me to believe that it will give more local knowledge on each part of the state.
As it's not out yet, I haven't read it so I can't say if it's any good or not. It does pique my interest a lot & sounds very promising to me. If you fly fish in PA or make regular trips here & want to bring the fly rod along, this might be the book for you. It's supposed to become available on February 1st & you can pre-order a copy HERE.