Do tu think Fullmetal Alchemist: Brotherhood is improving than the first series?

I do. I believe the darkness brings más intensity to the series. I feel closer to each character and the struggle that both Alchemists and Homunculus go through on a más personal level. en general, general I feel the story streamlines it in just the right way and each episode has something to offer. The ending is outright amazing.

yes.. brotherhood looks better to me..
they got an awesome job in the animations (you can compare) even the producers say they are so proud on the new anime (i've read that on an anime magazine). and i like how it is so faithful to the real arakawa-shi's (manga) story.