Ah, I've had two 86SE's with each (ST and Eibach) and the same shocks. Here's what I found:
The ST's drop the car about .5" more than the Eibach's but the Eibach's have a better ride. Eibach dropped was about 1.5", ST about 2".
Both are noticeably firmer than stock with the ST's being a bit too hard at times on rough roads (I care about ride quality). I think the Eibach's are a better spring for ride.
With the Eibach's, you will likely need to use the stock jack to get the car up enough to get a floor jack under it. With the ST's you will definitely need the stock jack.
If money is an issue, the ST's are good enough that I wouldn't shy away from them but I admit that since I had the Eibach car to compare, I removed the ST springs and put the stock springs back in and sold the springs.
I was able to get the front end aligned with both springs using Moog adjustable ball joints in the front.
Handling seemed to be about the same. I can't say that in everyday driving there was any real difference. Maybe at the limits there is. Both cars have the Addco rear bar.
Finally, both will fall out of the perch in the rear so when you jack up the car, make sure the spring is positioned before you lower it.
With Eibachs:
[This message has been edited by TK (edited 03-08-2003).]