While the title character's eternal task of hunting stray demons lends itself to a "monster of the week" structure at first, Vampire Hunter Miyu reveals itself to be a fascinating character study. The teasing glimpses into Miyu's heart and past are fully satisfying in the final few episodes, making the anime far more rewarding than the mundane (though equally pretty) OVA. While I would have appreciated less of the episodic approach, it does give a feel for the "daily grind" of hunting creatures of the night that prey upon the weaknesses found in humankind. The high school sequences are lighthearted, but retain some shade, through Miyu's bemused detachment. Miyu seems destined to view her human "friends" from a distance, and a careful viewing brings out her constant melancholy. She is morally colourful, or rather, exists outside moral ethics.
The action scenes are interesting, but are clearly meant to complement the character moments, not the other way around. With tinges of nihilism and a taste of inevitable suffering, I found this series had a fairly moody tone. I recommend this one for the patient. ^_^