As the title says, relatively speaking LP have done a great job at fitting in ample info on so many places into a, relatively speaking, small book (the book is huge compared to a normal book, but compared to everything it has in it,it is small).
We found most of the information that we needed, plus more and the brief history of each place was actually really helpful as well as the customs etc section of each country. Most people assume they are the same in all of these countries, and while there certainly was a lot of repetition there are key differences that are very important and LP makes a good point of these.
The only complaints I have are that with it being written by different authors, some sections are 100x more useful than others. For example some of the authors had amazing information on transport which helped with budgeting and getting an idea of our different options and routes. Others had lists of companies to contact- most only by phone, which I am sure is more than useful when in the country, but was useless for pre planning with, which is what we were primarily using the book for. This was the same with sights covered- some authors focused on museums etc., others on outdoor things which meant we have had to supplement our reading with online research too (this would have been done anyway, but doing it while reading made it easy to see which authors were the history/museum buffs and which were the more adventurous). While this is one of the benefits of using LP in this case it was a definite downside for us more than it has been when using other LP books. It might sound like a small complaint, but if you're using it for pre planning as we are then it wont be too helpful for finer details. and you might not want to carry this huge thing around with you in your backpack to have the numbers etc provided when in the country when you can find these vendors quite easily when on the ground.
The other complaint is that, like with any large book, with extensive reading and fingering of pages sections begin to fall out. As I read through our list of countries sections from each country became loose. After 2 days of having a look through the book looked like it was years old. Again, not too much of a problem for us as we're only using it for pre-planning, but a big problem for someone who wants to carry it around for a few weeks/months in their backpack.
I was also surprised at how inaccurate some of the prices were, yes it was published last year, however with an increase of 100 - 150USD in some of the prices quoted in the book (and this is the official advertised prices through the same websites mentioned in the book) our original budgeting was WAY off. We always expect a slight difference as things are always changing, but we were shocked by a few that had big differences.
All in all, it is a good book for pre planning, but probably more useful for having with you on the road, but it is a bit of a brick to carry around if doing longer journeys like us.
definitely worth the money if you're visiting more than one country in the areas, otherwise get one of the country specific guides which is half the size and has triple the info.