It's a lovely dress, I'd wear it (and own similar) and I'm a busty size 20. I'm surprised by people saying it wouldn't suit those with a bust or apple shaped, this is exactly the kind of style that suits me and is recommended for us. Open neckline, fitted waist, good sleeve length, all good.
My only concern would be that I find Seasalt dresses are cut small in the bust, and sizing up leaves you with too much fabric elsewhere. But it's worth trying to see if it works for you.
Seasalt do good quality clothes. They're not a young brand, you won't see teenagers in there, but they're clothes that will last and won't be out of fashion next summer.