My children have seen Dr. Cain a few times when they have been sick and there was not an open spot with Dr. Ruff. One thing I have noticed about him is that he is more aggressive with treatment than Dr. Ruff. That may be a positive or a negative depending on what your preference is.
He does not take the time to interact with children in the way the other Dr's at the clinic do, but it is obvious that he knows what he is doing. He is more of a "strictly business" Dr.