When it comes to books and the movie counterparts, I have a pretty firm philosophy. I believe one should always read the book first. Throughout my life, this has led to some late night reading sessions - I clearly remember being in high school and devouring The Silence of the Lambs as quickly as humanly possible before a Friday night trip to the movies. And I have passed this philosophy on to my kids (or mandated it?) with the Harry Potter films: you don't read it, you don't see it!
And my other steadfast philosophy has been that the film usually: falls short of the book, can live up to it occasionally, and never surpasses the author's original work. The occasional films that I think live up to the books are definitely The Silence of the Lambs (the way they shot that ending sequence of Clarice on the wrong, but right, doorstep was JUST as chilling as the book), The Harry Potter films, The Martian, A Time to Kill, The Hunt for Red October, and Bridget Jones' Diary, to name a few.
When it comes to conveying a setting, for me, films actually have a slight advantage over written descriptions and I think this was definitely the case. Brooklyn and Ireland were standalone characters in the book and all of the crew behind the camera did an amazing job in this regard. The glimpses of everyday life during the 1950s in both settings were so evocative: the buildings, the dance halls, the stores, the beaches, the people, and the COSTUME DESIGN. Love love love.