First of all, keep in mind that I'm a bit older than average manga readers.

Art: It's bad. Character models and drawings are nowhere near good enough. When in action, it's very difficult to see what's going on, especially in early volumes. It's slowly improved but at the end it's still just at an acceptable level.

Story: Good for the most part. It's terrible at the first 3 volumes but then the story goes back to the beginning and things are well explained. This is the best part of the story (golden age). After that, when Guts found new companions, story got illogical and boring. At times, it feels like Moon's Sailor.
The author's obsession with sex and rape causes excessive uses of these in the manga. At times it feels like porn.

When I got to volume 30, I lost all my interest and just skimmed quickly to the end. The ending is non sense.
Not recommended obviously for grown-up readers.