By far the only strapless bra I've ever worn that is both comfortable and doesn't slide around. After wearing this one a few times, I've actually thrown out all my other strapless bras and bought the other two colors of this one.

It's true to size for me - I'm 34A, and size 34 for this bra is perfect. I haven't had any issues or concerns with it slipping. Can't say this speaks for those with bigger cups, but if you're an A-cup, I 100% recommend this.