I love the tanks with the built in support. I purchased this black top in a size small. ( I am 5'11" tall and wear a 34C and have a 28 1/2 waist). It fit snugly in the bustline but perfectly in the midsection but I loved the style so much that I bought the white one, but chose it in a size medium. Unfortunately the medium white was too big, causing the piping around the bustline to curl under and the midsection does not seem nearly as tailored as in the black. I still wear both- but find myself fidgeting with the bustline on the white one. I am not sure if I am in between sizes or if the sizing is different between the colors. My advice would be size up in the black and size down in the white.
Lisa recommended this style