It all depends on what you want and what are your expectations. A good place to look is Africa hunting forum. Look in the deals section and you can also look up hunt reports for outfitters. If you cant find a hunt report for an outfitter you are considering, ask questions or move on to another outfitter.
Many places in South Africa are high fenced. Large operations, you will never see the fence. Some animals such as warthogs, duikers and such go through or under the fence and it does not matter. I always ask about the size of the concession, if it is fenced or free-range.
If you are planning on going this year, you may wish to ask about how they are doing with the drought. Some areas are experiencing losses due to drought.
I have hunted with KMG Safaris and with Tootabi Hunting Safaris and had a good time. In May I will be going with Rhinoster Hoek Safaris and LJ Hunting Safaris. All of these operations are in the East Cape of South Africa.
Spear Safaris and Tholo Safaris mentioned above have good track records and I have seen good reports but I have never hunted with them.