Ref the discussion above, there is more to calving ease than just birth weight. The shape of the calf's head and shoulders play a big part. Fleck calves tend to be big and square on both. I remember thinking last spring how those new born F1 calves look like they're a month or two old!  The very knowledgeable breeder I bought my Fleck bull from told me clearly "do not put him on heifers".

Regarding disposition, my Fleck bull was docile enough when I first got him but as he got older he got very aggressive, especially late this past summer. As good as his calves are, he is no longer here. I can't have an aggressive bull around my kids and grandkids, not to mention myself. I'm planning on keeping one of his F1 bull calves out of one of my best cows and see if I can get a bull with Fleck growth and Hereford disposition.

I'll stick with my Schu-Lar Hereford bulls as my primary bulls, at least for now.