I am a long time user of Chantelle memory foam t-shirt bras. They are exceptionallly comfortable, high quality, and look seemless under colthes.
I've noticed that the bras start to loosen and ride up after a few months. They need to be adjusted to the middle clips, then the last clips within one year of purchase, and start to gap at the top despite delicate handwashing with a liquid lingerie soap. I decided to switch from a 34C to 32C. The 32C cup is the size of a B cup so I ordered 32D which is a perfect fit...so comfortable, nice and tight, and stays firmly in place all day. Will definitely order again.