Bar none the highest performance Shorthorn bull I ever used was Jam's Uh-Huh. I've mentioned him on this site before. His calves grew so fast that if I hadn't seen it for myself, I wouldn't have believed it. They were among the larger calves I've had at birth, too. I used a son, Oakview Generator, for a year or two. Dale Studer borrowed him for summer calves one year and told me his son told him those summer calves would fit right in for size with the spring calves. That was probably close to 20 years ago. Another son I raised, Oakview Ignition, was out of a 7/8 Dollar II cow and he had even more performance. I only used him a little bit mostly because of his white legs. When the Uh-Huh calves were young, our neighbor, who raised some of the old style fullblood Simmentals, would stop by at least once a week and comment about how he had never seen calves grow so fast in his life. They weren't perfect by any means, but they did grow. Uh-Huh's pedigree is a very interesting combination of genetics. I've had good luck in the past with the infusion of some old Maine genetics. I've had calves out of Dollar II, Cunia, Covino III, Capone, Epinal 81E, Cygne, and probably a few others I can't remember and liked them all in combination with the other genetics I had. The Cunia offspring were not particularly fast growing, but they made the best cows of the bunch. I had a Cunia female out of a Rodeo Drive cow that was a tremendous female, type wise. I lost her after only a calf or two, though. Another Cunia daughter, out of an AFK Powerplay cow I believe, raised a heifer out of my herd bull, GR Coptop Trampas, that Dale Studer bought and won the Minnesota State Fair with. On the other end of the spectrum, my experience with Double Stuff, Windstar, Outrageous, etc., was that the WW and YW EPDs could not be negative enough. If I just wanted to raise fast growing, good feeding commercial cattle I don't think I'd be far wrong using a son of Covino III out of a Dividend or Leader 18th cow on my main cow herd.