I really love Mercedes Lackey and I don't understand how anyone else could possible. The writing is straightforward and serviceable. She makes every point explicitly and laboriously, enhanced not just by italics, but by emphatic italics. She writes dialect in the most atrocious way I've ever seen; my understanding is that good dialect is communicated 90% through word choice and only 10% through phonetic spelling. She uses phonetic spelling even on words where it does not make any difference. Every to is a t'.
But I think I mentioned recently, the main thing about her books is that everything is so neat. There's actually a passage in this one, Foundation (no relation to Asmiov's), that spells this out. Our main character, Mags, is trying to figure out why the Heralds go around being awesome heroes all the time, and his mentor (I'm not going to get into explaining Companions here; it's way too My Little Pony) says "We try to make things fair."
Mags protests that life isn't fair, and Dallen replies, "'Life isn't fair' is nothing but an excuse people make to justify bad things they do. But why shouldn't life be fair? What's keeping it from being fair? Those same cruel, mean, and evil people." This is said in all seriousness, and I think it's a main theme in her work: things are fair until someone makes them unfair, and it's up to the good guys to bring the fairness back. Nature's fairness.
This is so far off of the way the real world works that I hope nobody needs me to spell it out with words like "cancer" and "tornado." But almost all of her books believe this--that hard work always pays off. That the good guys always win. That plans come to fruition.
And not only fair, things are tidy. She's big on the details that make great worldbuilding, but her worlds actually run way better than the real world. I remember a behind the scenes feature about Star Trek that I saw once, where they showed that the futuristic stool the guy was sitting on was an apple crate with a futuristic cushion. That's what the real world is like, but her world is set with the fantasy world equivalent of futuristic stools made of as-yet-undiscovered alloys.
This sounds like hate, but it's really love. There's a beautiful, satisfying simplicity to her stories--the morality there is the morality of the world we all wished we lived in. And that's why I still read them.
That and the inside references for those of us who have read the rest of her books. I'm a sucker.
I will say, one of my favorite books of hers was The Black Swan, and one of the reasons, I realized today, is that it has the most complicated character--someone who falls in between good and evil, and discovers this. The path to redemption there is far more littered with obstacles--the bad guy is more formidable--than in any of her other books. But the palace kitchen is still run like clockwork.