DC resistance doesn't really tell you much about how the pickup will sound, given that in normal operation it will never have any DC current flowing through it. Agreed, milliVolts would be more useful - if we knew all the other test parameters like what strings were used, distance from pickup to string, how hard the strings were hit. More useful still would be a graph of frequency response or something like the tone guides on the Deymour Suncan pickup site. But then I wonder, who actually buys guitar pickups based on DC resistance or frequency graphs? All I ever do is head for the mp3s and decide which one sounds best to me.