I love this dress sooo much. I am wearing it to a ball and wanted something long but off the shoulders.
The colour is stunning although the material is thinner than you might think. I guess this is good because you can dress it up or down.
As a guide: I am about 162cm, 52 kg, no boobs, broad shoulders and not much of a waist and the size 8 was perfect for me. I'd say going bigger is a good idea because I was going to get a 6 but my ass would not have fitted! Definitely measure your bust etc. before buying; the website's style guide is pretty accurate.
If you're thinking of buying it - do it!