I think that there probably need to be a couple different designs, because we have different issues.

I've got big ribs & shoulders, small breasts that have been with me long enough to be showing the effects of gravity, and prominent nipples. I want something that holds me in place, smooths over the "headlights", but doesn't compress me even flatter than I am. So, I want some shape, some coverage, some support. But I don't need anything like the support of my more well-endowed sisters.

And it needs to be big enough for my ribs, but small enough for my (lack of) boobs! For some reason the sport bra makers seem to think that women with small boobs also have teeny tiny little rib cages... Not me!

I went into the local Macy's, and asked about a specific Champion sport bra in a 36 A. The lady says "Oh, you wouldn't be able to get that." I say, "Well, I already have one, so I know they make them. Can you check if they have any in stock at any of your other stores?" She says "Oh, no need to call... I'm sure they wouldn't carry anything like that." Did she learn this at their How to Drive Away Potential Customers Seminar?