Service station guys dont give a rats a$$ about your car, since its not their own. Therefore always try to take care of your car yourself, because noone cant do it like you could.
They dont take of their rings, or watches, which ruin your paint finish.
They use the same cloth for washing the tyres, undercarriage and then the same cloth which has a gazillion of tiny rough particles attracted from the tyres and undercarriage, goes onto ruining your clear coat, scratches, swirls, you name it, it give you that.
Surf is not meant to wash cars with, you can wash your tyres with it ok, but not the cars body, it would dry your paint like anything, and leave behind an extremely rough paint finish. But it is quite famous amongst our local service station detailers.
Pros
Im sure most of us cant afford automated machines like karcher at home, which cost a lot, so the fast running water/air out of their service station hoses, removes dirt very well.