This is a GREAT Dress. I am a full size 6, so when the review's said "run's large" I was worried. There is no way I wanted to get a 4! I ended up getting a 6 and an 8, but the 6 was PERFECT! If you are a small 6 (especially with small shoulders and small rear end) you need to get a size 4 for sure. The open back was a hit. I got no less than 50 compliments from co-workers at my company's annual Christmas party. I have a small chest and no bra was necessary. Their was extra material, but it didn't look bad at all. This dress works well for full and smaller busted women alike. Overall I would highly recoment this dress, I was sooooo glad I rented it!