Thank you all for your comments.
Kent--I do appreciate that Rick's books are not comprehensive guides like AAA, etc. I have been using them for over 10 years and have learned to pick and choose from his selections, because his criteria do not always match mine, especially in terms of location. For London, Paris and Venice, for example, we choose to stay in totally different locations than his choices. In Switzerland, we go to villages that are not even in his book.
For Vernazza, I feel like his choices give a much broader sampling, not just a few selections. There are many options for a very small place. It is like he has tried to bring order out of chaos---so those of us who don't like the idea of just showing up and seeking a room can reserve in advance and count on the reservation and price being honored. And we can view websites and see what it is we are reserving. And from the "New Ethic" announced by Rick for Vernazza, we hopefully can count on promises being kept.
A listing in Rick Steve's book is almost a guarantee of success, especially for small businesses in popular sites in Italy. I have seen a number of hotels brag on their website that they are "Rick Steves recommended." So when a popular place like La Marina is not listed in Vernazza, I have to wonder why. Did they choose not to be listed, for some reason? Or did they decline to subscribe to the "New Ethic" which is basically honesty? It would be nice to know which.
Terry---thank you for posting your personal experience there. This is exactly what I am seeking---personal recommendations. It sounds like exactly the type of place we would like.