We used Cuda
https://selectsiresbeef.com/bull/hereford/behm-100w-cuda-504c/ the past 2 years, got some really nice replacement heifers and have a 2nd set of calves due by him this spring but are all out of semen on him but based on 1st impressions would not hesitate to use him again.
Got our eyes on 2 bulls to try next, probably leaning towards GO King E33 out of the Oschner program
https://www.qualitybulls.com/hereford-herd-sires. One of the co-owners is in our state and got to see him in person at their production sale before he was going to be loaded up and headed to another of the owners place later that day and thought he was a good looking bull. The other is BG LCC 11B Perfecto 84F
https://www.streamlinegenetics.com/polled-bulls/semen/detail/id/8372
We do 1 round of AI then cleanup with our own bull S Coventry Y02 4D who we offer AI on too as we like his calves just as much as the AI sires we use and hoping some others can benefit too by using him. Our biggest issue is being a small cow herd can't go too heavy with the herd bull else we get too much of the same genetics so we use AI to introduce new bloodlines while trying to keep our calving season fairly tight.