One of the problems with something being truly good is that every so often it becomes a victim of its own success, and in a sense that's what happened with the fans of Full Metal Alchemist.
Arakawa Hiromu's tale of two brothers and their adventures in alchemy is one of the most well known stories in anime and manga to date, and has spawned a horde of games, a movie (with a second one planned), numerous doujins and fanfics, piles of merchandise ranging from tatoos to chibi plushies, and two very different anime series. The story itself is very typically shounen at times, however there is a depth to proceedings that belies the initial look and feel of the manga. While things begin innocuously enough, it's not long before the reader finds themselves wrestling with moral, religious, and even philosophical motives and actions as the Elric brothers make their journey towards their destiny.
Enough waxing lyrical, on to the nitty gritty. Anyone familiar with Arakawa's other works, especially her one shot manga, will undoubtedly find some surprising similarities to certain events and situations that occur in Full Metal Alchemist. The reason for this is because Arakawa had the foresight to test out various ideas in another form and format before adapting them for use in her flagship title, and this refinement process shows throughout the story. Although this is a shounen tale in the truest sense, there's a degree of complexity and innovation which has been carefully applied in an effort to draw the reader in, and this is one of the hallmarks of Arakawa's storytelling style.
As with any work though, there are a few areas that could have been improved upon. In an effort to lighten the mood from time to time the mangaka has seen fit to apply a few doses of comedy here and there, and while stories like Raiden 18 make it clear that Arakawa has some skills in that department, the application of humour in Full Metal Alchemist is sometimes a bit haphazard. That said, it seems like the mangaka herself also had a similar realisation as the tone of the series becomes much more serious during the latter half, and the frequency of comedic moments drops quite sharply. Surprisingly, the humour is less of a distraction and more of an anodyne for the reader during the later stages of the story, which is a testament to the idea that "less is more".
The artwork is very typical of the mangaka, however once more there is that look of refinement about the characters and settings, and even some of the action sequences. One big plus is that the reader is given a more visual, and sometimes visceral, look into the author's world than one might find in other shounen manga. That said, Rumiko Takahashi's InuYasha is a serious contender in this department, but like that manga, Full Metal Alchemist also suffers from the same problem - the highly stylized characters.
The main issue with the design is that some people may find it doesn't suit their tastes, which will in turn impact upon their appreciation of the story. That said, as an advocate of more individualism in manga and anime, it's nice to read something that remains true to the author's style as there are far too many titles that look identical to each other (e.g. harem romantic comedies and about half of the shoujo manga out there).
As for the characters themselves, suffice to say that the development of the lead roles is very good indeed, and the supporting roles are given a healthy amount of space to shine as well. One of the more interesting aspects is the pace at which the characters are developed throughout the story, and a big plus is the degree of attention given to the "bad guys", especially later in the series. It's a sad fact that shounen tales are filled with shallow antagonists who serve no other purpose than to give the lead character a wall they must "beat down" in order to move the story forward, and while Full Metal Alchemist contains the basic elements of this type of progression, it manages to mask them far better than most action manga out there.
Is there a major downside then? Well, unfortunately there is, but it's one that's very much dependent on personal taste. The reason why the Full Metal Alchemist franchise is a victim of its own success is because of the original anime adaptation of the unfinished manga.
Now one of the problems that fans have is that the two versions of the tale are wildly different in terms of atmosphere, story and character mentality (basically they're like chalk and cheese). The main issue at hand is that while the manga version of Full Metal Alchemist is an excellent series, the original anime adaptation is becoming maligned and misunderstood because it deviates too much from Arakawa's story. Personally I consider both to be equally good, just not in the same way.
Here's what I mean.
Arakawa's manga is a very good story that incorporates a number of typical shounen aspects like never giving up, trusting in one's friends and allies, etc, and while the tale is excellent in both content and execution, in all honesty, it lacks a degree of "darkness" that was inherent in the first anime. One of the things that struck me about this dissonance was the fact that the whole theme of obsession seems to peter out by the end of the manga, whereas the first anime actually ended with that theme still running strong.
Now, some of you maybe a little confused by that perspective, especially as both tales feature the same characters to a degree, however one look at their respective endings will begin to make things a little clearer, and pay particular attention to Alphonse Elric as he is the reason why I consider the two tales to be so very different (and if you're still unsure, then feel free to ask me about it).
It's pretty obvious that I enjoyed Full Metal Alchemist immensely, however my only real gripe with the manga, especially after reading Arakawa's other works, is that there are too many occasions where it feels like the author has purposely moved away from a theme or situation that was used in the original anime, and this can make parts of the story feel a bit rushed. That said, this is actually a minor problem as the whole tale fits together extremely well, and in terms of content Full Metal Alchemist is easily on par with Takahashi Rumiko's masterpiece.
What Arakawa Hiromu has given us is a work that is truly good, despite some minor niggles here and there, and while there are some typically shounen aspects to the tale, Full Metal Alchemist, like Inuaysha, is a far cry from what one would consider a typical shounen manga.
Isn't it ironic then, that the two of greatest shounen tales weren't written by men?