Vagabond is best in longform, and unlike Berserk I can't really think of a quick hook for it unless you're already interested in the subject matter. What I can tell you is that if you aren't quite into yet, it definitely keeps raising the bar as it goes along, I mean it doesn't just evolve, at a certain point it's like a revolution, in art, storytelling and message. To be honest, the Vagabond you're reading isn't on the level yet of what it will become, but, is a necessary part of that payoff, experiencing Musashi's physical and mental journey and transformation. In that sense, the story is almost a metaphor for itself; from a typical adolescent state, to something special and transcendent. You've only read about the first arc, which amounts to the exposition for everything that is to come on Musashi's journey and rematch with the Yoshioka; it's really just begun, and from there, the story, characters and philosophical aspects really start coming into better focus, which is the real the strength of the series, though the art and action only becomes stronger as it goes on as well. I can only tell you to stick with it, for it will be more rewarding than you can possibly foresee now.
Also, having a place to discuss and dissect these things can certainly makes it more stimulating, and that's what the
Vagabond Inn was created for, so please feel encouraged to share your thoughts there and get some feedback.