I learned everything I needed to know about Stephenie Meyer and Twilight when I heard that Meyer did not do any research on vampire folklore. Seriously? If you’re writing a series of novels about vampires, how do you not research vampires?
I have already admitted my tendency toward Tolkien Syndrome or World Builders Disease. Say what you will, I like to flesh out how a fantasy world “works” to the extent that things make sense at a macro scale. Part of that is being aware of one’s source material: the mythological store rooms from which we draw our common ideas about magic, gods and demons, mythical creatures, and the like. You won’t be surprised, then, to know that I like to read stories where it is clear the writer has done his or her homework.
Let me hasten to say, I certainly don’t object to writers doing something new and different with a mythological concept. I just want them to give me a wink to let me know that they know what they’re doing.