Update after actual travel: My initial opinion is unchanged - this book has some useful information that is not in the Rick Steves guide, but overall I think Steves is better (but, if you don't want to spend money and have a Kindle Unlimited subscription, I think you can get by with just this book). The information in this book does seem to have been updated to 2018 - i.e. most of it is fairly current, but the costs data, given the sky high inflation of the last couple of years, is out of date.
This is a review of the Kindle edition, which is dated 2018 but is based on the 2013 12th edition - some of the text appears to have been updated to 2018, but how current it is I'll only know when I go (I'll update this review after I travel, which probably won't be until 2023).
I'm using this book (which I'm reading using a free trial of Kindle Unlimited) to draw up a rough itinerary for an extended trip, I will buy the Rick Steves guide before I start making bookings - in my experience Steves is generally better than LP, but he's highly opinionated and he only covers things he's interested in (so, not contemporary art or fine dining), so it's good to consult a 2nd guidebook, particularly for a long trip.
This book is very thorough, covering a wide variety of destinations, and of attractions in each destination (though, as other reviews note, it does not cover the islands!) - so, given the above, I'm satisfied with it. It doesn't give much detail on how to avoid queues, you have to go to Steves for that. It doesn't given much detail on trains either, you have to go to The Man in Seat 61 for that. There are very few photos, you have to go to Google or IG for them (or don't and be surprised).
The formatting of the Kindle edition is awful (large sections are simply unformatted), which makes the book hard to follow, as well as looking ugly. The links to Google Maps would be awesome if they worked properly, but often they don't (they often take you to the lat-long, rather than to the pin for the actual attraction). The links to websites do work and are very handy. The search function is very handy too. Kindle is the sensible way to carry a guidebook (who wants to lug a huge brick around the world?), so it's so sad that there are so many kinks in this Kindle edition, and that the newer edition isn't available on Kindle!