As a compromise it works very well. Yes there are various forums where people can ask for advice and birding spots in a certain vicinity, but nothing beats the feel of a "real book" to thumb and browse.
Yes you can collect all the various regional guides but will you use them so often? it can be argued regular birders/twitchers will know the areas anyway. Casual birders will enjoy this. I visited Norfolk, Suffolk, Mull and Speyside in a two week period. This book helped a lot - and continues to do so.