what it really comes down to, as to whether or not you'll enjoy it, is the mindset you go into it with. If you watch it, expecting to see Blade or Kabuto, you're not going to find what you're looking for. Hibiki is very much so a drama, with action sequences, rather than an action series, with drama.
While there is a lot of detail put into each character, and you get to know most of the primary and secondary Oni quite well, at it's core, the series is basically a high school student's coming of age story. You get to know Asumu quite well, and watch him progress from his initial introverted nature, to his finding someone he can look up to, and emulating him, to the eventual conclusion where he understands that to truly grow up, he needs to be his own man, and forge his own paths, instead of simply following the path others have set before him.
I can say with complete honest that the series was a joy for me. And is the only series that I still watch annually after it's initial run (I'm on my 5th viewing of the series currently) but again, the series is certainly not for everyone. If you're a regular viewer of Dorama you'll probably find it more enjoyable.