When performed properly, all of the treatments (Portrait Plasma, Fraxel re:pair, and Active FX) give excellent results with skin resurfacing. When investigating the technologies and doing my "due diligence" before incorporating Fraxel re:pair into my practice, I spoke with many respected experts in the field.
It is my impression from these discussions that the safety window for avoiding permanent scarring is greater with fractionated CO2 lasers. One of my colleagues reported that he had seen some burns with plasma resurfacing. There can be complications with any technology, but in my practice I want to use the safest and most effective tool.
Whichever technology you choose to go with, the most important aspect is to choose your treating physician most carefully. Be well.