User blog comment:TonyMutu/Thoughts on 2003 anime/@comment-1618178-20130109041552

I always advice people to watch Brotherhood as a whole even if have watched FMA 1 first, since there's little differences in the first few episodes, but those little differences are actually very important to the whole picture of the series.

Again, I'm not a very great fan FMA 1 as a "adaptation of FMA". For me, personally, it is great as a series for itself, but it's just not FMA. It's something else entirely. The characters are others, the story, their actions... It would be like saying that the 90's movie "Clueless" is the same as the 1800s novel "Emma", or that "The Diary of Bridget Jones" and "Pride and Prejudice" are the same "piece of work".

That being said, what I CAN tell you, Tony, without spoilers, is that all those parts in the first bits of FMA 1 that you felt were "fillers", well, they're not! Actually, it is quite the contrary: THOSE where the real plot of FMA and that were left behind by FMA 1 as not to spoil the manga as it was released. So, it felt like fillers because they couldn't follow up on them, not because they were not important to the story. In the FMA manga, there probably isn't a single episode or "bit" that could be considered "filler". They all serve a greater purpose and, many of them, only a lot further down the road. From the Priest on Lior to the death of Hughes, it all has a greater meaning in the story.

So, what I suggest? Now that you have finished FMA 1 and liked it, go on and read the manga/watch FMA:Brotherhood!! I'm not promising you're going to like it better than FMA 1, but it will sure be a lot more "tied up" as a series.