I probably wouldn't have spent the money if I hadn't needed the lights right away (They really aren't that much more expensive than 300E Euros, but over twice what the lenses would have been if they had been in stock). But now that I did it, I am pretty happy.
15 to 15 3/4" sounds about right. I measured my car at different spots before I did the sportline conversion, and Sportline dropped the height about 1" front and a bit more in the rear. The before and after pics are in the 'cars' tab under Sportline article to see the difference in looks.
Measuring from the wheel star to the bottom of the fender is a tiny bit under 14 1/2" on mine at all 4 wheels, which means ~15 1/2" before I did the Sportline.
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
Click to see 87 300E