I actually prefer the movie and there's actually more to the movies than what's in this book and I'm only talking about the first 4 movies which are the only ones I liked so I order to continue you basically have to watch the movies!
I never read the 2015 sequel and maybe it would all flow together if I did but the movies must be completely different than what hellbound heart and the book sequel actually are and at this point it's like two entirely different things judging from what I've heard in book reviews of the newer book...