Technology continues to improve with both Thermage and Ultherapy. The Thermage CPT helped make treatment less painful, but it is not without pain. Newer off-label uses of other tips may help facial areas benefit, especially under the neck. Ultherapy has improved their transducers and software allowing more gentle treatment and increasing the number of lines of treatment. What seems to be true for both technologies ( I use both in my practice) is that the lower energy per pulse (thermage) or line (Ultherapy) makes it more comfortable, but then the number of pulses / lines must increase to obtain a good result.
Regardless of the choice of Thermage or Ultherapy, if a beneficial result is obtained, it might be a long term result as the collagen produced as a result of the treatment is not going to go away. Granted, we age with time, and there will be a constant sagging of the face but having one of these treatments will help allow us to stay ahead on the aging curve. Some patients get a second treatment at six to twelve months for continued improvement.
The information provided in Dr. Shelton's answer is for educational purposes only and is not intended to constitute medical advice. The information provided should not be relied upon as a substitute for consultations with a qualified health professional who may be familiar with your individual medical needs.