I have been using a beefmaster bull since I started my commercial herd about 4 or 5 years ago. Bought my cows from a gentleman who has been running beefmaster bulls on his commercial herd exclusively for about 20 years (and he has been in the cattle business for over 50 years). His family buys over 20 beefmaster bulls per year. He retains heifers, sells some replacements, and retains ownership of his steers through the feedlot. With all that said, I've pulled one calf in 4 or 5 years (and I may have jumped the gun on that one), my cattle have very gentle dispositions, they tolerate the heat well, they're great mommas, and my calves gain well. My bull covers the cows and he has never shown any aggression. I'll try to post some pics later. Gotta get rolling this morning.