Size down - loose,, flowing material - love it!
This dress is light, airy easy and comfortable to wear. i love the colors and pattern. it looks wonderful with or without a belt. i sized down from a 6 to a 4. i position the front of the dress material closer to the neck so it flows longer at the back. although i am a size 6 the under slip fits perfectly in a size 4. i prefer the dress without a belt but it also looks good with a belt or a jacket or long cardigan. 
this dress is a keeper!