I changed these more than a year ago and the handling is terrific, but the rear shocks seem to be very hard when they have to compress rapidly.
It almost bangs when going over a bump.
Anyone else have this problem?

 

Yes mine seem very very stiff. I always figured it was my car bottoming out when I hear that bang. I'm not sure...

 

I have the SLP valved Bilsteins. Didn't notice a difference in ride from my old Decarbons.

 

What springs are you running with the Bilsteins? Bilsteins from the factory are vavled for stock springs. Anything lower or with higher rates, are going to be "hard" on the shocks.

 

I have the Eibach Pro-Kit. I bought the Bilstein HD's. They seem to produce a pretty decent ride quality, but its not like stock for obvious reasons being it is a lowered car.

How would the car react differently with revalved Bilsteins? Would it make really that much of a difference?

 

That's the problem...deCarbons suck and don't have a very good ride. Quality shocks should produce a superior ride, even with lowering springs.

With revavled Bilsteins, the shocks would be able to properly damp the springs. Sam Strano has them vavled for the exact spring rate and driving environment of your particular application. He is a championed SCCA racer and knows his stuff very well. www.stranoparts.com

Koni SA would be my top choice, though. The revalves are a somewhat cheaper alternative.