It's a great site and i have bookmarked it, but not sure how accurate it is. I have the marble paper Dasha and there's no way I could have gone down one size. I am normally an 8 in dresses and I had to have a 10. I don't think it runs large at all. I tried on both an 8 and a 10 in the store and definitely needed a 10.
Also I found this to be frustrating (but true):
It seems as if DvF generally designs for an A/B cup size bust
You know, she's been making this dress (the wrap) since the 1970's. Dont you think she'd have learned in the last 30 years or so to design it for larger-chested women as well? ~sighs~
__________________
"Good taste shouldn't have to cost anything extra." - Mickey Drexler