How do you define "best"?
I define a good groomer as a company who takes great and exrtreme care on the details, uses the right tools for the right job. Example - a good groomer will use blower instead of chamois to wipe dry. He will also use different applicator for different parts of the car. Sponge to wash car body should not be used to wash wheels. Post buffing no finger prints - the groomer should not even use bare hands to open or close doors.....
A good restorer is harder to fine. The machining process has to be consistent - else you will see uneven surface only in extreme light conditions - the "halo" effect. After S4C, not many good restorers around. Most are using fillers to mask swirls.