I am also a 10F and I bought a Genie Bra over 6 months ago and I love it, I now have 6 of them and wear nothing else, I have the medium size. I did try to wear 2 together but felt like I couldn't breath, I have worn them only while breastfeeding and pregnant so I am unsure what it will be like support wise once I am empty and shall I say saggy after feeding 4.

Thought I might add, I originally bought the black, white and beige combo and they are fantastic, I then got the blue, pink and purple combo and although they are the same size and brand they don't seem quite so firm, not sure why, they are ok still I just go for the plain colours first, i just feel they hold a bit better.

I just read the other posts and thought I would also add that I don't drop through wear, they seem to hold me in place but mine is the genie bra so maybe they are a little different even though they look the same.