Elvis' former wife, Priscilla Presley, saw the movie and had nothing but positive things to say about it. So, fans of Presley who wonder how accurate the film is should trust the adaptation as being mostly spot on.
While I might not be a die-hard fan of his, I did grow up listening to Elvis, because it was all my dad played. He ordered a cassette series of his greatest hits when I was probably eight or so years old, and he still has them today.