We used some Polled Plus semen that we bought from Golden Link in Nebraska. The calves were all born unassisted out of 3 year old or older females. Overall we really liked the calves...grew well and were very stout and muscular. We may use more of him next year.
My impression of the Thorne operation is that they are very showring oriented. If you are considering showing them and are less concerned with performance I would consider them. Their website used to have a daily diary written by Mrs. Thorne that gave some good insight into their operation, selection criteria, culling criteria, etc.
A couple operations that I am familiar with that are more commercially oriented are Golden Link (mentioned above) and Brinks in Kansas, though they do show some as well.