Which Interventional Device - expert independent opinion of interventional devices

I used this machine for over 3 years, I love it for small lesions that need a 4cm probe or less. The 5 cm probe just doesn't work. I have used the 5cm probe at least 4 times with sub-optimal results. A friend from fla. says he has similiar experience. Otherwise great machine. Great knowing that the cells actually cooked, not that they "should be" cooked.