All the difference...
Get a bronze brush. It makes all the difference. I brush my skis before I wax ( after I clean them), and you wouldn't believe how much extra glop comes out compared to using a nylon brush. I don't race, but am always breezin' by my buds on traverses and flats. The beauty of a good tune is realized when you are pillaging the 15" of new while your friends are 50 feet behind poling on traverses.