LOVE this top!
Usually tops this this fall down on me (the band is tight, but the material slips a little too low and I continually have to pull it up), but not with this top! I wore this bralette four days in a row when it first arrived, and even fell asleep in it once. I forget I'm wearing it, it's like a second skin.
I'm between a medium and small and decided to go with small (US bra size 32 D, although I don't wear "real" bras anymore- usually a S or M bralette). It was just a bit small the first day (not small enough to return though), but over time the material gave enough for a perfect fit, while the elastic waistband and in the straps stayed strong. I love this top SO much and will definitely be getting more colors when I'm able to!
I'm going to see how the fit might change after this first wash and potentially switch to medium for the next color, but most likely will stick with small.
If you're on the fence about getting this top- go for it!!