I submitted a YA fantasty to SC - unfortunately I only found out about the Open Door at the weekend submissions were ending, so I fear it's not as polished as I would've liked (yes, it's complete and so on, but still, I would've liked to spent more attention on it!). I sent it in just before midnight on closing day.
I don't quite know how I feel about submitting an 'old' book. I worry that it doesn't represent the best of my work that I'm producing now. Saying that, I have worked on it quite recently, and it's good to get it out there and let publishers decide for themselves whether they want it!