This was my favorite bra when I was twenty something.  I finally broke down and got another one few days ago.  It is just as cute as I remembered.  Perhaps too cute if you are over 35...
It's very sheer.  So if your shirt is on the slightly sheer side, a lot of details will show.  The cup is not very stretchy so I think it's adequate for support but maybe not if you are C cup and up.  I think the cup sizes are true to most standard sizes.  Unfortunately, I am more of a 34A than 34B, but the smallest cup size is B in these bras.  So the cups are a bit "empty" and has some loose material leaving some creases.
Still, I am happy with the purchase.  It's definitely something every girl needs in her lingerie.