The cups on this bra seem to run at least a cup to two cup sizes big. The wires and band are very firm and snug, which is pretty painful and I've only had it on for a few minutes. The bra seems to be going for a half-cup effect, but it's still a three-piece cup with horizontal seaming, which seems like it won't accommodate upper fullness or tall roots, even in the correct size.
This was my first fit try. I bought a 30D and 30C from Pour Moi brand. This bra did not fit at all. The band was too small (I could not even hook the bra). This surprised me, as it is also a 30 band, but it seems more like a 28 band or even less. The cups are sooo narrow, I could not even fit my breasts without putting on the band. They are also very shallow. It was only to try the bra sizes for the first time, so it's OK if it does not fit me. The quality is great, the fabric is very good quality and soft, and the lace details are very beautiful.