I had no experience with tennis prior to my lessons with Dallas, and was fairly nervous. He was friendly, clear, extremely patient and quickly put me at ease. I am not very athletic, but he focused on the positives while providing helpful feedback for improvement.
After four lessons, I had the opportunity to play socially with friends. I don't think I will be going pro anytime soon, but I was able to play casually and do fine while actually enjoying the game (anyone who knows me will know that is a testament to Dallas' teaching skills).
I can only speak to his skills when teaching adults, but he was very patient and I would expect him to be great teaching children, also.