The band on this bra does run quite tight and were more likely fit a 28 or 26 than a 30, but other than that it's a very good compression bra. The lack of underwire means there's really no encapsulation, but everything is held tight to the chest and is effective even in high-impact running.
This bra is great as a pure compression, no-encapsulation bra but it does run at least a band or two small, so make sure to size up. It can be difficult to get on but once it's there, it really holds you down, even with high impact running. I would estimate this bra's actual size as around 26DD.
the 30" band is more like a non-flexible 28". No stretch to it. The should straps only adjust by less than 1" very inflexible, not stretchy like a normal workout bra. The inner lining is a bit odd, and tends to bunch up, making it visible on the outside of the fabric. Not a fan.
The tag says 30DD but it fits like a 30D/28DD. I'm still keeping it at least for a while, but it is absolutely too small for me. It does manage to keep everything locked down with some test jumping jacks but I haven't used this bra actually working out, so I don't know how it will hold up yet.
I used to wear just stretchy sports bras from Target, until I found this one cheap on Amazon. I love it! Yes, it smooshes you, no it doesn't look good under clothes, but it's so comfortable for running! The band is very firm, but wide, so it doesn't dig in at all. The "cup" material (there aren't actually individual cups) has some stretch, but not so much that it's loose after a couple hours. The padded straps are very comfy, and I don't have a problem with the velcro on the straps coming undone. Women with large chests might have a problem with the velcro straps. Also, so far I don't feel too hot in this bra, but I'll have to see what it's like come summer.