I might try swapping pads - say, between the Dia Compe Edge brakes and the Campagnolo Record's, just to see if the effect is all in the pads. I wrote this though, with the intention of reviewing each brake as a system and presenting my opinions based on experience with what you get when you buy 'x' brakes. There are also valid differences between brakes here from the same manufacturer, made in the same time period ( contrast the Dura Ace vs. 600 and the Edge vs. RGC's) and those differences make me comfortable in thinking that it isn't all in the pads.
Danny