For those who have replaced their springs with Eibach, I have yet to see a complaint.
After research, I narrowed my choice between H&R and Eibach and chose the later because of testimony of users. After 6 months on my car, I concur. The drop is just right, about 1 1/4' inch up front with about 1"+ in the rear. My wife stills enjoys the ride and I have not noticed any harshness at all.
The bump stops remain as OEM. I do bottom out at dips and have to be very careful with wheel stops. But that is to be expected!
Put them on, you love the look and you'll appreciate a little better handling.
Although, they are not the fix all for an improved suspension, they are a start. You could always look into the Dinan stage 2, etc.
I did not need spacers in my opinion, however, that could be debatable!
P.S. Add some HRE's and then you'll be hooked up!
P.P.S. leburpor, you need to wait about 400 miles for the springs to set and you may want to wait until then to align. If you are going to track, you may consider a different camber setup for that purpose, etc.