I have used Ultherapy as it is FDA cleared for non surgical facial and neck tightening. I am not aware of any head to head studies comparing Ultherapy to Thermage. Read the Ultherapy ebook provided on the link below.
I have been using the Ulthera technology for 4 years and I personally have found the results to be superior to Thermage. The software on the unit was updated over a year ago and the treatment is even more effective and more comfortable.I personally do the treatments myself reather than delegating it to my staff.Perhaps this is why my results are consistently great.