There are other differences between FMA and the manga/Brotherhood. For instance, when Ed and A try to bring their mother back and Ed loses his leg and Al his whole body, then Ed sacrifices his arm to bring Al's soul back; in both instances Ed passes through the "gate", but in the anime the gate is filled with crazed Shadow Children that steal Ed's limbs, while in the manga there is only one very civil Shadow Child named Truth who carries on a short conversation with Ed before his shit gets robbed by dark hands. And that's one of the little differences! The endings are completely different, the story progresses in different ways (in the anime Scar kills Nina in an alley while her father is arrested but in the manga Scar kills them both in their house), stuff like that. It might as well be a completely different story for all the changes they make.
Personally, I watched FMA first when it aired on Adult Swim, then watched Brotherhood later on Netflix because my fiance is such a huge FMA fan and she talked me into it. I enjoyed the order I watched them in, and it seems kinda obvious that Brotherhood was made for the sole purpose of shoving continuity in the face of the FMA anime (a lot like DBKai is to DBZ - as if to say "I follow the manga and FMA doesn't"); I think if you watched Brotherhood first then you might not like FMA that much, you'll look at it and say "that's not what happens".



















