Stiff springs are bouncy. After hitting bumps on the road, they tend to harshly vibrate up and down. In order to control that, you're gonna have to set the shocks to their stiffest setting. Otherwise, the shocks can't control springs that are rapidly moving up and down only 1/16" or so.

In my case, what I have are soft springs on stiff shocks and it works well on the street. If I hit a bump and say, the spring wants to compress 1/2", the shock is easily able to dampen that. Now if I had stiff springs and it wanted to compress 1/16", the shock wouldn't be able to catch that and the car will bounce.

As for the drawbacks, say I'm taking a long curve and the outside spring wants to compress 1". At first the shocks will catch and the car would remain relatively flat, but as you get deeper into the curve, the shocks, no matter how stiff, will eventually compress after about 2 or 3 seconds and you'll get body roll... that's the only case in which I see you'll need stiff springs.

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Black 96 GS

-Manny