Extremely professional, friendly, conscientious. Have been a patient for many years, along with my extended family. Not only that, but Dr Koff volunteers his services internationally (which gives him lots of great stories to tell while I'm unable to speak ;)).
Last I checked, Dr. Koff was not part of any insurance/discount plan... and his prices _are_ a little high. Then again, he's recommended cost-saving procedures that easily could have saved many years of "slightly higher" prices.