I've read all of the books several times (including Silmarillion and the others), so I'm definitely informed when it comes to the 'lore' and 'story.'
I don't care about the liberties taken in the series. It's not supposed to be a duplication of the books...and even Tolkien himself wasn't sure about the final development of some characters.
Tom Bombadil was perfect.
Elrond is perfect.
Sauron is perfect.
Galadriel is okay.
Durin is perfect.