i got a set of bsw "woofer" in my front door. they don't sound so great compare to the hk that I have in rest of the speaker setup.
the hk setup sounds pretty decent to me for an upgraded factory setup. if you are looking for better, you'll need to upgrade the whole setup instead of just changing speakers alone - budget $3k installed. it's not worth it consider you will never get that back when selling the car.