A substantial portion of this book sees Harry Potter being hunted by Death Eaters with pretty much nowhere to go. It did get a bit tedious reading of Harry, Ron and Hermione disapparating from field to field up and down England, oftentimes spending days or weeks doing next to nothing. All the while, Harry is trying to piece together information about the Deathly Hallows which his two friends don't believe in. Their friendship is put under heavy strain and Ron storms off in frustration, only to return later. It's not pleasant reading.
But it does pick up eventually and builds up nicely to the finale where Harry returns to Hogwarts to take on Lord Voldemort.
What was striking was just how different the book is to the movie. Or in other words, how much they had changed the movie adaptation when compared to the original script in the book. As someone who had watched the movie before reading the book, I was confused about how exactly Voldemort had died. It is crystal clear in the book.
Professor Snape's role and intentions are brought into the light at the end after Harry extracts his tears before he dies. We learn that Snape is in fact the true hero who has always been loyal to Dumbledore and who never ever lost his love for Lily Evans, Harry's mum. His love for her was more powerful than ever contemplating siding with Voldemort again..
I had liked Snape from the start without knowing if ultimately he was really with Dumbledore, or Voldemort. So it was highly satisfying and emotional when in his memory he summoned his doe patronus to demonstrate his love for Lily. That moment also clarified that it was Snape who led Harry to the sword of Gryffindor in the lake earlier in the story.
A great finish to the book and what a fascinating journey the Harry Potter series has been.