I love writing for both middle grade and young adults so I can't really pick one over the other. I do think I have more of an audience at the middle grade level since I write more light hearted, humorous novels and right now, like Deena said, YA is a lot of dark stuff currently. Sure you can find some light stuff but when you walk into a bookstore most of the stuff faced out is dark. I miss the pink cover days! The middle grade kids are still open to the lighter, fun books (Yay!) and I love the fan mail I get from the middle grade readers too! So yeah, I can't really decide between them, both are fun for me to write. I just finished writing a new YA and I'm about to revise it but once I'm finished with it it's back to middle grade for my next one.
Kristina, Miss Author in Action