Here's some "scientific" information for you. In my younger days I AIed to about every bull imaginable. From Leader 21 to Clark to Cunia to Double Stuff to Leader 18th and everything in between. The only one that had a noticeable, and I mean noticeable, positive influence on performance, both weaning and and post weaning, was Jam's Uh-Huh. I've mentioned it before, but you could actually see those calves grow. There were several bulls that sired calves that were noticeably poorer performers. These bulls were generally known as "club calf bulls." Quite frankly, there will never be a perfect set of research in anything as long as it's run by humans. Our family has been ASA members for nearly 70 years. I can count the number of times anyone asked me about EPDs on my fingers. I use them for myself, but there are too many variables to be relied on.