Just watched this, not boring, but it shows excessive artistic liberty
Jo Kastner took too much crative license with this movie.
I agree that it's pointless to retell a book, in a conversion, as it is in the book. Nothing to say about the little changes here and there other than:
1. This is a Saint Pete/Hannibal with mountains and cowboys, definitely an important departure from the original. It didn't annoy me, but was sort of a mood-killer.
2. The ending and the reveal make sense, but [WARNING SPOILERS] to negate the three sequels in which both Tom and Huck are featured, having Twain say he never saw Huck again after he eloped with Jim, was downright unfaithful to the original.