I have the Pro Kit, not sure if there's a Sportline setup for our cars or not. OEM shocks/struts are the only option for us until Corksport comes out with theirs.
Ride quality is just fine. It's not harsh, it's not bouncy, it's a good ride. It won't kill you on long trips. It's a very comfortable ride. Compared to stock, it is just more solid, not as sloppy. Obviously, some more aggressive dampers would be great but in the mean time it's a good solid ride of DD use, long trips, whatever. No complaints here and I've have mine on for 8 months and almost 8000 miles.