I worked at a shop that used SW, though I did not paint much there. The SW seemed to perform pretty well, and the cars that we painted that came back once in a while for minor repairs looked really good even after exposure to pretty harsh conditions. As far as I remember, the products were all from the "Ultra 7000" line, though the only clear I used was the 639 "Super Glamour" clear. It sprayed pretty nice.
P.S. I use PPG now, and I guess I prefer it, but usually we prefer what we are used to. All the different paint lines I have used have good and bad products in them, the trick is getting to know the products and making slight adjustments in technique to compensate for the differences.