I bought an S and it's very large on me around the chest, waist and arms. The material is thick but there's a weird double lining right at the top of the breasts of around 1inch which shows through because the rest of the dress is single layer. Also, the sleeves are weirdly positioned so the whole dress moves weirdly when moving your arms.
I guess if you manage to get your size right, it's cute enough for a summer dress given the price.