You should definitely read it. I can't speak for how much you'll enjoy it personally, but it is one of my favorite works of fiction, and I consistently come back for re-reads and discussion amongst other fans. Since you seem very interested in it, I think it will at least meet your expectations.

The story is basically centered around two characters: Guts and Griffith. Guts is one of the most awesome protagonists in manga. Sometimes you will love him, sometimes you may hate him, but either way you will find yourself being moved by his struggle, and he will give you more fist-pump moments than you can count. As for Griffith, without spoiling, I'll just say that he sets the benchmark for outstanding villains in manga. This guy is so disgustingly evil while still having understandable motivations and actions.

As for the timeframe of when it will end, who can say? If Miura continues at his current pace, then I could see the story lasting for well over another decade. But that shouldn't scare you away from the series. After the prologue (which is around three volumes long) there are three HUGE arcs that are completed, and we are well into a fourth arc. There is so much great content that you won't feel disappointed, and when new chapters are released you can participate in active discussions on this subreddit with other fans.

Don't rush through it, and enjoy the ride! And don't forget to come back to this subreddit and give your thoughts on the story (good or bad). You can never have too many Berserk fans!