This is indeed my favorite anime, and I have experience with anime.
Yes, its starts off pretty slowly but I think its a good way to show Erin's world, and honestly, I don't mind the slow paced beginning. Its soothing.
Its unpredictable and beautiful. I like the art style because its different than any other anime.
That's what I like about Kemono no Souja Erin. It's different. Unique. Emotional. Beautiful.
Audio is beautiful, I love all the songs and learned to play them on the piano :D
Overall, I really recommend this anime to all ages, it will surprise you how good it is.