If that Patagonia bra is the same one I tried (and I'm pretty sure it is), I have no idea why they call it "high impact." It gave me way less support than even my daily wear bras. I think I have camis with shelf bras that give me more support than that thing (seriously). For $45, I sent it back.

To the OP, it really depends how much bouncing you plan to do with your body, and how much you want to completely eliminate bouncing up top. For running, kickboxing, high impact aerobics, etc., for me nothing but extreme compression will do (small B cup but very floppy ). Yeah, I've got headlights, I just line 'em up and deal with it. There are always Nip-Its or the like if it really bothers you.

For cycling, lifting, Pilates, Yoga, etc., when all you need is something that gives you freedom of movement and wicks sweat, you have a lot more options.