It all depends on the company you are talking about. You have to remember these "big time show companies" became "big time show companies" by having quality not quantity! I know you see them all selling numerous calves, but some of them have just 4 or 5 really nice cows and they are flushing or IVF'ing them to the good bulls and putting the embryos in recips. I dont know how quickly it is taking off in other parts of the country but around here it is becoming increasingly popular to basically lease recip cows. I know a couple big operations and all they do is run recip cows. If you are going to need recips you call and book the number you need, they set them up to be implanted when you need them and then they feed the cow and calve em out. The contract is that you will purchase every calf resulting from one of your embryos at weaning for a predetermined amount, I think its generally in the $1500 range. A lot of show cattle producers around here are utilizing this and all they actually own are a few head of good donor cows and the calves that they actually have for sale. It works great for people that dont have the land to run a lot of cows and calves.
As far as AI'ing, most of them are most likely going to be at least trying to settle all their cows AI and then running a good clean up bull on them. There are still some out there though that do it all the traditional way, but its easier to improve your genetics and you typically have access to a wider variety of good genetics through AI.