For almost a year I have had a very love-hate relationship with Berserk. On one hand, the art, story, setting, and characters are all extremely well-thought-out and fascinating. But on the other, there are innumerable slogs through boring fights and gratuitous (& needless) depictions of sexual violence.
I would say that The Golden Age arc (lasting 102 chapters) is, one of, if not the, most well-written arcs of manga ever. The character writing is the best I've ever seen in any piece of media, including western fiction. The main trio, Guts, Griffith, and Casca are extremely nuanced and fleshed out. The pacing is steady, never too slow or fast, despite encompassing a very enriched(&large) plot. It's impressive how masterful Miura is.
And after this arc, the quality never fully reaches what the Golden Age Arc had once again. There are a few moments, and a few arcs that can almost match up to it, but can never compare. For example, the Falcon of the Millennium Empire arc is also very good. But the fight scenes with Guts are excruciatingly boring. Unlike the battle scenes in the Golden Age, which all felt meaningful and like they had a purpose, these ones are just... soulless... Guts kills a bunch of giant monsters in the same style with the same dialogue... for no purpose.
This doesn't take away from my rating that everyone-- who can handle the subject matter,-- should read Berserk... But... It's good for people to know that it isn't what the manga community cracks it up to be. I definitely recommend it. But just, take what you hear about it with a grain of salt.