Fullmetal Alchemist Brotherhood, now with some sleep:
Now that I've had a chance to sleep on it I've decided that the series is very good, but overall when compared to the first series it's kind of a draw. The below is just opinions, obviously.
What Brotherhood does better than the original:
The story and the fight scenes. The story is much better and more coherent. Well, as coherent as a story about magic alchemy can be, that is. ;P The motivations of certain characters makes a bit more sense, we learn more about Hoenheim and how he fucking plays into everything, and the progression of Ed and Al feels more natural. I also liked how the conclusion felt more... well, conclusive. I also highly enjoyed the fight scenes, super bad ass animation and choreography.
What Brotherhood does not do better than the original:
Overall the character artwork and animation are better in the original series, as well as the background paintings and music. Additionally the original had better pacing. Brotherhood was running full pelt almost non-stop until around episode 48 and then suddenly crawled for the next 16 episodes to draw out the final battles. It was too fast to begin with, and the sudden slow-down at the end creates a jarring pace.
Overall both series are quite good, and I do prefer BroHood by a smidgeon. But they're kind of a draw in terms of "which one is better".