Some pad compounds/systems take a good while to fully bed in. When I bed in a new pad/rotor set at the shop it can take about 3-5 miles of grabbing good before they grip nicely. On my Avid BB5 mech on the city bike actually took a couple weeks of commuting in the city to fully grip. A soft compound would be faster, but I would not let anything out the door to a customer without at least an initial burn in.