Great teachers, awful owners.
Sunborn is a great place to ride as long as you avoid the owners.
The staff providing many of the lessons are outstanding as a general rule. Very well qualified and work to meet the needs of the riders. The horses there appear to be well cared for as well. The schooling horses are mostly cared for by the riders themselves, which engages the riders in learning to actively care for the horse.
The owners are pretty awful. It's a topic no one actually talks about there, but everyone knows it. They're blatantly disrespectful and seem to feel no obligation to be civil to the people who employ their services. Julie is one of the owners, and she also gives lessons. She is an excellent rider and teacher, but is nearly abusive of her students. If you can endure the abuse, she'll turn you into a good rider.