My first impression of this episode was, "Woah, they really sped through Ed and Al's backstory like a runaway train." Seriously. This episode covered a lot of the material in the flashback that took up chapters 21-24. There was Ed and Al with their mother, Ed and Al researching human transmutation, Ed and Al studying with Izumi (glossed over here, but given at least a little peek), attempting the transmutation, failing, the aftermath, and Ed becoming a State Alchemist. All in one episode. With an interlude in "present time" where Roy learns that Isaac was knew Xingese alchemy (subtitled "pharmacy" in my sub of choice, making sense because Xing uses their alchemy for medical purposes). So, it was packed. Perhaps too packed.
Actually, my second impression was that, yes, there was quite a bit stuffed in a single episode, but what we missed out on will probably be covered at another time, and trying to see this from the perspective of a new viewer, it came across a little better. It's not nearly as good as the episodes that cover Ed and Al's past in the first series, but all the important bits from the manga involving the human transmutation and its aftermath were here, and glided along pretty smoothly, even in their speed. The the alchemic taboo scene itself was amazingly well done in both animation and mood. I easily felt disturbed at the events unfolding, but also felt sorrow for the young boys.
I'm also adjusting rather well to the new voices. Winry and Riza's, for instance, both got to work out in a little scene from the manga where Riza meets Winry at the Rockbell house while Roy talks to the brothers and Pinako. There was a similar scene in the first series, but it was a more knowing scene, and the circumstances were far different. This one is more innocent. The voice actresses both did well here. I get a sense of an inner strength in the new Riza that should come out later with no problem.
So, anyway, it's a lot to swallow, and I have every reason to believe they'll be returning to some of this later. Next week: Lior! I keep forgetting that Lior isn't in the desert in the manga, and that Rose is white. I'm so used to the tanned Rose.