The eibach pro kit is the best kit for a 6th gen. With as low as it makes the car, the ride is still remarkable smooth compared to other springs kits, and obviously much smoother the coil-overs or cutting springs. They are easy to install, and arent all too expensive.
If there is another brand out there worth looking at thats a better ride, let me know.

I have the Eibach Sportlines and love them. They drop the car about a half inch lower than the Proline but I've never really had problems with it being too low. It made my car hanlde a lot better too.