THIS MAY CONTAIN SPOILERS! I just saw "My Little Pony The Movie" I must say I thought it was really good. The animation was beautiful and the music was used to nicely compliment the story. I really liked Twilight's arc. Some of the previews and spoilers I heard from other bronies made me concerned that Twilight might be portrayed as OOC or a jerk. Luckily that was not the case in my opinion. You could easily see how Twilight's insecurity leads to her anxiety, guilt and frustration to the point of lashing out. Actually Twilight seems like the realist in the movie being that she was appropriately on guard about the new characters while the other Mane 5 seem a bit more naive and overly trusting, and Twilight gets more desperate so her stealing the pearl while wrong did make sense. Rainbow Dash was great and I loved the scene where Twilight rescued Pinkie, and Tempest's voice actor was amazing. This movie reminded me of the movies I grew up with and watched when I was recovering from surgery as a kid in the best way. I like that Tempest still had a broken horn at the end because it makes a good statement on what could be considered a disability for a unicorn and about acceptance, that she did not need to cured to be whole as a pony. I felt Sia's song was about Twi "weathering the storm" and her "soul growing" i.e character growth in the movie. 
However the movie had a bit too many characters, some things aren't explained at all, and the movie is paced like an episode rather than a movie in that the ponies could have actually taught the new characters about friendship gradually, especially Tempest since they have a full length running time to use.