In short, all of the ones you have listed are made by different manufacturers. All are pico second lasers. But all are very, very, very different. If you have stubborn pigment, personally I'd have you do the PicoWay with a combination of Zoom and Resolve heads which means you'll get a double whammy for fractionated and non-fractionted wavelengths and at different depths. Of those you listed, this is by far the superior choice and has the most versatility. "This answer has been solicited without seeing this patient and cannot be held as true medical advice, but only opinion. Seek in-person treatment with a trained medical professional for appropriate care."