I read all of this series when i still couldn't read English in my native language (Brazilian Portuguese) during that time the site that did the translation, Jikai (defunct for quite some years now), liked to do their projects with only volume scans so i read this in the highest quality and BOI... i never read something that quite catches the same feeling.
Maybe it is nostalgia i won't deny, i dont doubt that there is other series as good or better than this one, i won't even say this is without failing but...... it is just special, it is from a time when things were simple from an author that poured his heart on this, ES21 has that feeling of discovery where the characters are truly growing trying to find their way in life, the comedy is SPOT ON, the action simply amazing and all of this is conveyed by art that you simply dont see every day.
Murata Yusuke-sensei is an artist in a league of his own, i know there are some more famous than him but this guy... this guy knows how to draw, there is never a wasted panel, never an image that doesn't convey exactly what the story want.
And obviously, the story is just as good, every character was constructed so that they feel like real people, sure the highly stylized and hyper-real setting makes them have pretty noticeable quirks but this is what makes us feel the weight of their lives.
I laughed, I cried, I cheered... this manga is one of my first, if not the first complete series, and i am biased but if you have time and want a ride of a life, Read This One, i guarantee you won't regret it.