Epd's aren't exact I agree, but they are the best thing you have to go on.  No matter how good the bulls numbers are half of a calves dna comes from the cow.  One other point I would make is the milk epd is the most overated epd there is.  The diference between a bull with a milk epd of 20 and one of 30 is 10 pound at a calves weaning time there are tons of ways to get or lose 10 pounds by weaning time to put so much enphasis on milk.