The special effects do not inhibit story and character development as so often happens with scifi/fantasy. Great pacing, it did not feel like an almost 3 hour film.
Only two elements detracted from the experience for me. First, the villain of the movie falls too much into the stereotypical military "kill the natives" idiot. Similarly, the reason for removing the natives - mining a rare mineral - with no consideration of other profitable resources the planet might offer was jarring. Second, the aliens were still a bit too human. They probably should have had 4 eyes for example. However, other than the humanoid aliens, the alien flora and fauna were well done, with good attention to common ancestry & evolution principles.