Should the backing plate be the same size as the pad or are certain pads not actually true to size? Someone else mentioned they had a 5" pad that was really 5.5" when measured. The LC backing plate says their 5" works with 5.5" or 6.5" pads. The new Meg's DA kit recommends their 6" BP with the 6" MF pads. Is it possible the pads are actually a little larger than 6"? I would imagine the more support the better, but is it just preference? I seem to get a little too much mushrooming when I apply pressure on a 6.5" pad on a 5" BP.