There are things that McKinley does very well: the loner girl, her comfort with being out alone in nature, her interactions with critters (horses, cats, and dogs). This stuff is all brilliant. A girl who teaches herself how to fight dragons? That's a fabulous premise. Other aspects of the book I wasn't so keen on: the whole destiny thing, the dreams, the mage. But fighting dragons, that was really well done, and handled surprisingly realistically.
It's rather a slow, thoughtful sort of book, but it's easy to understand how it has become such a touchstone in YA literature. I'd love it for no other reason than the young woman finding a way to evade sexism within her culture. That didn't feel anachronistic at all.