Springs off an E30 M3. Will lower around 1" all round. Good if you live around rough roads and don't like to replace oil pans. Your car will not be slammed, but it will eliminate some of the gap and tighten up the ride a bit.
If you have a late body style ( 88+ ) the lower rear arches will make it look even lower.
I cannot say what the ride is like, but this is what I've read:
"The M3 springs were a nice compromise between stock and H&R in both ride height and ride quality"
"a good deal stiffer"
"best bang for the buck"
"best compromise of everything"
[ $195 ]
Digitalwave's car with M3 springs.