sizing question

I've searched google multiple times, i've read blogs, i've checked the memories. But, I would like the opinions and experiences of people I can interact with and ask questions to, so i came here:) Recently I bought the wonder cookie op, i have a few ap dresses and they all fit very well, but i have never had any experience with unshirred dresses. To those of you ladies with a 34 DD cup or bigger, have you ever been able to fit into an unshirred dress nicely? How generous are the measurements of unshirred dresses? Thanks!