Christie's mysteries are literally the "cozy mystery" category. And I love the light feeling she has in most of them. I also love how accurately she portrays characters. It was Christie who introduced me to sociopaths...those oh so charming, without morals killers of hers. (Though I was a lot older than 13 when I finally realized that's what she had done.) I don't think the term "sociopath" had even been invented when she portrayed one back in the 1920s. I love Christie's mysteries. I've read them all. Novels and short stories. The older I get, the more I appreciate Christie's insight into human nature.

But when you say this...

>I can rely on Christie to give me a mystery where all the pieces are there.

No, you can't.

You want that? Read the early Ellery Queen novels and short stories. The ones with the "challenge to the reader" where you have to turn the page to get to the solution.