I tried to buy that top and there was much too much fabric bunching around my waist -- I sent it back. I had hoped it could be worn open but you're right, would just flop at the sides. I think you need a long torso to pull off that top! Would love to see modeling pics once you work it out!
I agree there's a lot of fabric but i just loved the way it gathered and for me it was tight enough to give me some definition so I got it!